diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticPropertiesScope.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticPropertiesScope.kt
index d2be0dcd83a..d024f9eea98 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticPropertiesScope.kt
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticPropertiesScope.kt
@@ -296,7 +296,7 @@ class JavaSyntheticPropertiesScope(storageManager: StorageManager, private val l
             source: SourceElement
     ) : SyntheticJavaPropertyDescriptor, PropertyDescriptorImpl(
             containingDeclaration, original, annotations, modality, visibility, isVar, name, kind, source,
-            /* lateInit = */ false, /* isConst = */ false, /* isHeader = */ false, /* isImpl = */ false, /* isExternal = */ false,
+            /* lateInit = */ false, /* isConst = */ false, /* isExpect = */ false, /* isImpl = */ false, /* isExternal = */ false,
             /* isDelegated = */ false
     ) {
 
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.kt
index 1f087944649..1691a41e159 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.kt
@@ -645,7 +645,7 @@ class ControlFlowInformationProvider private constructor(
             is KtPrimaryConstructor -> if (!element.hasValOrVar()) {
                 val containingClass = owner.getContainingClassOrObject()
                 val containingClassDescriptor = trace.get(DECLARATION_TO_DESCRIPTOR, containingClass) as? ClassDescriptor
-                if (!DescriptorUtils.isAnnotationClass(containingClassDescriptor) && containingClassDescriptor?.isHeader == false &&
+                if (!DescriptorUtils.isAnnotationClass(containingClassDescriptor) && containingClassDescriptor?.isExpect == false &&
                     !containingClassDescriptor.isEffectivelyExternal()
                 ) {
                     report(UNUSED_PARAMETER.on(element, variableDescriptor), ctxt)
@@ -665,7 +665,7 @@ class ControlFlowInformationProvider private constructor(
                 if (isMain
                     || functionDescriptor.isOverridableOrOverrides
                     || owner.hasModifier(KtTokens.OVERRIDE_KEYWORD)
-                    || functionDescriptor.isHeader || functionDescriptor.isImpl
+                    || functionDescriptor.isExpect || functionDescriptor.isImpl
                     || functionDescriptor.isEffectivelyExternal()
                     || OperatorNameConventions.GET_VALUE == functionName
                     || OperatorNameConventions.SET_VALUE == functionName
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/psi/synthetics/SyntheticClassOrObjectDescriptor.kt b/compiler/frontend/src/org/jetbrains/kotlin/psi/synthetics/SyntheticClassOrObjectDescriptor.kt
index 115bdbf72a4..67882bb64fd 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/psi/synthetics/SyntheticClassOrObjectDescriptor.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/psi/synthetics/SyntheticClassOrObjectDescriptor.kt
@@ -74,7 +74,7 @@ class SyntheticClassOrObjectDescriptor(
     override fun isCompanionObject() = isCompanionObject
     override fun isInner() = false
     override fun isData() = false
-    override fun isHeader() = false
+    override fun isExpect() = false
     override fun isImpl() = false
 
     override fun getCompanionObjectDescriptor() = null
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/BodyResolver.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/BodyResolver.java
index a7a6402039a..604109a6eaf 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/BodyResolver.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/BodyResolver.java
@@ -166,7 +166,7 @@ public class BodyResolver {
             @NotNull KtSecondaryConstructor constructor,
             @NotNull ClassConstructorDescriptor descriptor
     ) {
-        if (descriptor.isHeader() || isEffectivelyExternal(descriptor)) {
+        if (descriptor.isExpect() || isEffectivelyExternal(descriptor)) {
             // For header and external classes, we do not resolve constructor delegation calls because they are prohibited
             return DataFlowInfo.Companion.getEMPTY();
         }
@@ -367,7 +367,7 @@ public class BodyResolver {
                     descriptor.getUnsubstitutedPrimaryConstructor() != null &&
                     superClass.getKind() != ClassKind.INTERFACE &&
                     !superClass.getConstructors().isEmpty() &&
-                    !descriptor.isHeader() && !isEffectivelyExternal(descriptor) &&
+                    !descriptor.isExpect() && !isEffectivelyExternal(descriptor) &&
                     !ErrorUtils.isError(superClass)
                 ) {
                     trace.report(SUPERTYPE_NOT_INITIALIZED.on(specifier));
@@ -428,7 +428,7 @@ public class BodyResolver {
         assert enumEntryDescriptor.getKind() == ClassKind.ENUM_ENTRY : "Enum entry expected: " + enumEntryDescriptor;
         ClassDescriptor enumClassDescriptor = (ClassDescriptor) enumEntryDescriptor.getContainingDeclaration();
         if (enumClassDescriptor.getKind() != ClassKind.ENUM_CLASS) return;
-        if (enumClassDescriptor.isHeader()) return;
+        if (enumClassDescriptor.isExpect()) return;
 
         List<ClassConstructorDescriptor> applicableConstructors = DescriptorUtilsKt.getConstructorForEmptyArgumentsList(enumClassDescriptor);
         if (applicableConstructors.size() != 1) {
@@ -617,7 +617,7 @@ public class BodyResolver {
         if (classDescriptor.getConstructors().isEmpty()) {
             trace.report(ANONYMOUS_INITIALIZER_IN_INTERFACE.on(anonymousInitializer));
         }
-        if (classDescriptor.isHeader()) {
+        if (classDescriptor.isExpect()) {
             trace.report(HEADER_DECLARATION_WITH_BODY.on(anonymousInitializer));
         }
     }
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationResolver.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationResolver.kt
index ebe4d729529..94a93a3cb01 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationResolver.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationResolver.kt
@@ -81,7 +81,7 @@ class DeclarationResolver(
             // TODO: report error on header class and impl val, or vice versa
             val (header, impl) =
                     getTopLevelDescriptorsByFqName(topLevelDescriptorProvider, fqName, NoLookupLocation.WHEN_CHECK_DECLARATION_CONFLICTS)
-                    .partition { it is MemberDescriptor && it.isHeader }
+                    .partition { it is MemberDescriptor && it.isExpect }
 
             for (descriptors in listOf(header, impl)) {
                 if (descriptors.size > 1) {
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt
index 404de14ec6f..a8a79d3ce0f 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt
@@ -250,7 +250,7 @@ class DeclarationsChecker(
     }
 
     private fun checkHeaderClassConstructor(constructorDescriptor: ClassConstructorDescriptor, declaration: KtConstructor<*>) {
-        if (!constructorDescriptor.isHeader) return
+        if (!constructorDescriptor.isExpect) return
 
         if (declaration.hasBody()) {
             trace.report(HEADER_DECLARATION_WITH_BODY.on(declaration))
@@ -633,11 +633,11 @@ class DeclarationsChecker(
 
         val initializer = property.initializer
         val delegate = property.delegate
-        val isHeader = propertyDescriptor.isHeader
+        val isExpect = propertyDescriptor.isExpect
         if (initializer != null) {
             when {
                 inInterface -> trace.report(PROPERTY_INITIALIZER_IN_INTERFACE.on(initializer))
-                isHeader -> trace.report(HEADER_PROPERTY_INITIALIZER.on(initializer))
+                isExpect -> trace.report(HEADER_PROPERTY_INITIALIZER.on(initializer))
                 !backingFieldRequired -> trace.report(PROPERTY_INITIALIZER_NO_BACKING_FIELD.on(initializer))
                 property.receiverTypeReference != null -> trace.report(EXTENSION_PROPERTY_WITH_BACKING_FIELD.on(initializer))
             }
@@ -650,7 +650,7 @@ class DeclarationsChecker(
         else {
             val isUninitialized = trace.bindingContext.get(BindingContext.IS_UNINITIALIZED, propertyDescriptor) ?: false
             val isExternal = propertyDescriptor.isEffectivelyExternal()
-            if (backingFieldRequired && !inInterface && !propertyDescriptor.isLateInit && !isHeader && isUninitialized && !isExternal) {
+            if (backingFieldRequired && !inInterface && !propertyDescriptor.isLateInit && !isExpect && isUninitialized && !isExternal) {
                 if (propertyDescriptor.extensionReceiverParameter != null && !hasAccessorImplementation) {
                     trace.report(EXTENSION_PROPERTY_MUST_HAVE_ACCESSORS_OR_BE_ABSTRACT.on(property))
                 }
@@ -696,7 +696,7 @@ class DeclarationsChecker(
 
         if (containingDescriptor is ClassDescriptor) {
             val inInterface = containingDescriptor.kind == ClassKind.INTERFACE
-            val isHeaderClass = containingDescriptor.isHeader
+            val isExpectClass = containingDescriptor.isExpect
             if (hasAbstractModifier && !classCanHaveAbstractMembers(containingDescriptor)) {
                 trace.report(ABSTRACT_FUNCTION_IN_NON_ABSTRACT_CLASS.on(function, functionDescriptor.name.asString(), containingDescriptor))
             }
@@ -712,17 +712,17 @@ class DeclarationsChecker(
                     trace.report(REDUNDANT_OPEN_IN_INTERFACE.on(function))
                 }
             }
-            if (!hasBody && !hasAbstractModifier && !hasExternalModifier && !inInterface && !isHeaderClass) {
+            if (!hasBody && !hasAbstractModifier && !hasExternalModifier && !inInterface && !isExpectClass) {
                 trace.report(NON_ABSTRACT_FUNCTION_WITH_NO_BODY.on(function, functionDescriptor))
             }
         }
         else /* top-level only */ {
-            if (!function.hasBody() && !hasAbstractModifier && !hasExternalModifier && !functionDescriptor.isHeader) {
+            if (!function.hasBody() && !hasAbstractModifier && !hasExternalModifier && !functionDescriptor.isExpect) {
                 trace.report(NON_MEMBER_FUNCTION_NO_BODY.on(function, functionDescriptor))
             }
         }
 
-        if (functionDescriptor.isHeader) {
+        if (functionDescriptor.isExpect) {
             checkHeaderFunction(function)
         }
 
@@ -789,7 +789,7 @@ class DeclarationsChecker(
             accessorDescriptor: PropertyAccessorDescriptor?
     ) {
         if (accessor == null || accessorDescriptor == null) return
-        if (propertyDescriptor.isHeader && accessor.hasBody()) {
+        if (propertyDescriptor.isExpect && accessor.hasBody()) {
             trace.report(HEADER_DECLARATION_WITH_BODY.on(accessor))
         }
 
@@ -829,7 +829,7 @@ class DeclarationsChecker(
     private fun checkEnumEntry(enumEntry: KtEnumEntry, enumEntryClass: ClassDescriptor) {
         val enumClass = enumEntryClass.containingDeclaration as ClassDescriptor
         if (DescriptorUtils.isEnumClass(enumClass)) {
-            if (enumClass.isHeader) {
+            if (enumClass.isExpect) {
                 if (enumEntry.getBody() != null) {
                     trace.report(HEADER_ENUM_ENTRY_WITH_BODY.on(enumEntry))
                 }
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java
index 2e5e38cb559..34a820a17e1 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java
@@ -875,7 +875,7 @@ public class DescriptorResolver {
                 modifierList != null && modifierList.hasModifier(KtTokens.LATEINIT_KEYWORD),
                 modifierList != null && modifierList.hasModifier(KtTokens.CONST_KEYWORD),
                 modifierList != null && PsiUtilsKt.hasExpectModifier(modifierList) && container instanceof PackageFragmentDescriptor ||
-                container instanceof ClassDescriptor && ((ClassDescriptor) container).isHeader(),
+                container instanceof ClassDescriptor && ((ClassDescriptor) container).isExpect(),
                 modifierList != null && PsiUtilsKt.hasActualModifier(modifierList),
                 modifierList != null && modifierList.hasModifier(KtTokens.EXTERNAL_KEYWORD),
                 propertyInfo.getHasDelegate()
@@ -1201,7 +1201,7 @@ public class DescriptorResolver {
                 KotlinSourceElementKt.toSourceElement(parameter),
                 false,
                 false,
-                classDescriptor.isHeader(),
+                classDescriptor.isExpect(),
                 modifierList != null && PsiUtilsKt.hasActualModifier(modifierList),
                 false,
                 false
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt
index 86160ee8bbd..12b87c0b6b9 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt
@@ -184,8 +184,8 @@ class FunctionDescriptorResolver(
         functionDescriptor.isInline = function.hasModifier(KtTokens.INLINE_KEYWORD)
         functionDescriptor.isTailrec = function.hasModifier(KtTokens.TAILREC_KEYWORD)
         functionDescriptor.isSuspend = function.hasModifier(KtTokens.SUSPEND_KEYWORD)
-        functionDescriptor.isHeader = container is PackageFragmentDescriptor && function.hasExpectModifier() ||
-                                      container is ClassDescriptor && container.isHeader
+        functionDescriptor.isExpect = container is PackageFragmentDescriptor && function.hasExpectModifier() ||
+                                      container is ClassDescriptor && container.isExpect
         functionDescriptor.isImpl = function.hasActualModifier()
 
         receiverType?.let { ForceResolveUtil.forceResolveAllContents(it.annotations) }
@@ -296,8 +296,8 @@ class FunctionDescriptorResolver(
                 isPrimary,
                 declarationToTrace.toSourceElement()
         )
-        if (classDescriptor.isHeader) {
-            constructorDescriptor.isHeader = true
+        if (classDescriptor.isExpect) {
+            constructorDescriptor.isExpect = true
         }
         if (classDescriptor.isImpl) {
             constructorDescriptor.isImpl = true
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/LocalVariableResolver.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/LocalVariableResolver.kt
index 3f77b3fb467..6419a4b293a 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/LocalVariableResolver.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/LocalVariableResolver.kt
@@ -153,7 +153,7 @@ class LocalVariableResolver(
                     variable.toSourceElement(),
                     /* lateInit = */ false,
                     /* isConst = */ false,
-                    /* isHeader = */ false,
+                    /* isExpect = */ false,
                     /* isImpl = */ false,
                     /* isExternal = */ false,
                     variable is KtProperty && variable.hasDelegate()
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverloadResolver.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverloadResolver.kt
index 1b583a01387..7727fc4f2e2 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverloadResolver.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverloadResolver.kt
@@ -252,7 +252,7 @@ class OverloadResolver(
                 if (isConstructorsOfDifferentRedeclaredClasses(member1, member2)) continue
                 if (isTopLevelMainInDifferentFiles(member1, member2)) continue
                 if (isDefinitionsForDifferentPlatforms(member1, member2)) continue
-                if (isHeaderDeclarationAndDefinition(member1, member2) || isHeaderDeclarationAndDefinition(member2, member1)) continue
+                if (isExpectDeclarationAndDefinition(member1, member2) || isExpectDeclarationAndDefinition(member2, member1)) continue
 
                 if (!overloadChecker.isOverloadable(member1, member2)) {
                     redeclarations.add(member1)
@@ -282,9 +282,9 @@ class OverloadResolver(
         return file1 == null || file2 == null || file1 !== file2
     }
 
-    private fun isHeaderDeclarationAndDefinition(declaration: DeclarationDescriptor, definition: DeclarationDescriptor): Boolean {
-        return declaration is MemberDescriptor && declaration.isHeader &&
-               definition is MemberDescriptor && !definition.isHeader
+    private fun isExpectDeclarationAndDefinition(declaration: DeclarationDescriptor, definition: DeclarationDescriptor): Boolean {
+        return declaration is MemberDescriptor && declaration.isExpect &&
+               definition is MemberDescriptor && !definition.isExpect
     }
 
     private fun isDefinitionsForDifferentPlatforms(member1: DeclarationDescriptorNonRoot, member2: DeclarationDescriptorNonRoot): Boolean {
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/ValueArgumentsToParametersMapper.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/ValueArgumentsToParametersMapper.java
index 6a4928fdeda..40a39900401 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/ValueArgumentsToParametersMapper.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/ValueArgumentsToParametersMapper.java
@@ -183,7 +183,7 @@ public class ValueArgumentsToParametersMapper {
 
                 KtPsiUtilKt.checkReservedYield(nameReference, candidateCall.getTrace());
                 if (nameReference != null) {
-                    if (candidate instanceof MemberDescriptor && ((MemberDescriptor) candidate).isHeader() &&
+                    if (candidate instanceof MemberDescriptor && ((MemberDescriptor) candidate).isExpect() &&
                         candidate.getContainingDeclaration() instanceof ClassDescriptor) {
                         // We do not allow named arguments for members of header classes until we're able to use both
                         // headers and platform definitions when compiling platform code
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/dynamicCalls.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/dynamicCalls.kt
index 1b45e594c81..e6056e10404 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/dynamicCalls.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/dynamicCalls.kt
@@ -98,7 +98,7 @@ class DynamicCallableDescriptors(storageManager: StorageManager, builtIns: Kotli
                 SourceElement.NO_SOURCE,
                 /* lateInit = */ false,
                 /* isConst = */ false,
-                /* isHeader = */ false,
+                /* isExpect = */ false,
                 /* isImpl = */ false,
                 /* isExternal = */ false,
                 /* isDelegated = */ false
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
index c674ba8fe53..5080895733c 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
@@ -61,7 +61,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
 
         if (descriptor !is MemberDescriptor || DescriptorUtils.isEnumEntry(descriptor)) return
 
-        if (descriptor.isHeader) {
+        if (descriptor.isExpect) {
             checkHeaderDeclarationHasImplementation(declaration, descriptor, diagnosticHolder, descriptor.module)
         }
         else {
@@ -100,7 +100,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
         return when (header) {
             is CallableMemberDescriptor -> {
                 header.findNamesakesFromModule(platformModule).filter { impl ->
-                    header != impl && !impl.isHeader &&
+                    header != impl && !impl.isExpect &&
                     // TODO: support non-source definitions (e.g. from Java)
                     DescriptorToSourceUtils.getSourceFromDescriptor(impl) is KtElement
                 }.groupBy { impl ->
@@ -109,7 +109,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
             }
             is ClassDescriptor -> {
                 header.findClassifiersFromModule(platformModule).filter { impl ->
-                    header != impl && !impl.isHeader &&
+                    header != impl && !impl.isExpect &&
                     DescriptorToSourceUtils.getSourceFromDescriptor(impl) is KtElement
                 }.groupBy { impl ->
                     areCompatibleClassifiers(header, impl)
@@ -201,7 +201,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
                 }
 
                 candidates.filter { declaration ->
-                    impl != declaration && declaration.isHeader
+                    impl != declaration && declaration.isExpect
                 }.groupBy { declaration ->
                     // TODO: optimize by caching this per impl-header class pair, do not create a new substitutor for each impl member
                     val substitutor =
@@ -217,7 +217,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
             is ClassifierDescriptorWithTypeParameters -> {
                 impl.findClassifiersFromModule(commonModule).filter { declaration ->
                     impl != declaration &&
-                    declaration is ClassDescriptor && declaration.isHeader
+                    declaration is ClassDescriptor && declaration.isExpect
                 }.groupBy { header ->
                     areCompatibleClassifiers(header as ClassDescriptor, impl)
                 }
@@ -408,8 +408,8 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
         with(NewKotlinTypeChecker) {
             val context = object : TypeCheckerContext(false) {
                 override fun areEqualTypeConstructors(a: TypeConstructor, b: TypeConstructor): Boolean {
-                    return isHeaderClassAndImplTypeAlias(a, b, platformModule) ||
-                           isHeaderClassAndImplTypeAlias(b, a, platformModule) ||
+                    return isExpectClassAndImplTypeAlias(a, b, platformModule) ||
+                           isExpectClassAndImplTypeAlias(b, a, platformModule) ||
                            super.areEqualTypeConstructors(a, b)
                 }
             }
@@ -421,7 +421,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
     // is java.lang.StringBuilder. For the purposes of type compatibility checking, we must consider these types equal here.
     // Note that the case of an "impl class" works as expected though, because the impl class by definition has the same FQ name
     // as the corresponding header class, so their type constructors are equal as per AbstractClassTypeConstructor#equals
-    private fun isHeaderClassAndImplTypeAlias(
+    private fun isExpectClassAndImplTypeAlias(
             headerTypeConstructor: TypeConstructor,
             implTypeConstructor: TypeConstructor,
             platformModule: ModuleDescriptor
@@ -429,7 +429,7 @@ object HeaderImplDeclarationChecker : DeclarationChecker {
         val header = headerTypeConstructor.declarationDescriptor
         val impl = implTypeConstructor.declarationDescriptor
         return header is ClassifierDescriptorWithTypeParameters &&
-               header.isHeader &&
+               header.isExpect &&
                impl is ClassifierDescriptorWithTypeParameters &&
                header.findClassifiersFromModule(platformModule).any { classifier ->
                    // Note that it's fine to only check that this "impl typealias" expands to the expected class, without checking
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/inline/InlineAnalyzerExtension.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/inline/InlineAnalyzerExtension.kt
index fdf6348fd07..0c88d9c0c70 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/inline/InlineAnalyzerExtension.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/inline/InlineAnalyzerExtension.kt
@@ -161,7 +161,7 @@ class InlineAnalyzerExtension(
         }
         if (hasInlineArgs) return
 
-        if (functionDescriptor.isInlineOnlyOrReifiable() || functionDescriptor.isHeader) return
+        if (functionDescriptor.isInlineOnlyOrReifiable() || functionDescriptor.isExpect) return
 
         if (reasonableInlineRules.any { it.isInlineReasonable(functionDescriptor, function, trace.bindingContext) }) return
 
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/AbstractLazyMemberScope.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/AbstractLazyMemberScope.kt
index c011bf1b5e3..9d1ac9d11fe 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/AbstractLazyMemberScope.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/AbstractLazyMemberScope.kt
@@ -72,11 +72,11 @@ protected constructor(
         // See getFirstClassifierDiscriminateHeaders()
         var result: ClassifierDescriptor? = null
         for (klass in classes) {
-            if (!klass.isHeader) return klass
+            if (!klass.isExpect) return klass
             if (result == null) result = klass
         }
         for (typeAlias in typeAliases) {
-            if (!typeAlias.isHeader) return typeAlias
+            if (!typeAlias.isExpect) return typeAlias
             if (result == null) result = typeAlias
         }
         return result
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
index a4f956aab8c..ab65df3f790 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
@@ -91,7 +91,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
     private final ClassKind kind;
     private final boolean isInner;
     private final boolean isData;
-    private final boolean isHeader;
+    private final boolean isExpect;
     private final boolean isImpl;
 
     private final Annotations annotations;
@@ -168,8 +168,8 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         this.isData = modifierList != null && modifierList.hasModifier(KtTokens.DATA_KEYWORD);
         this.isImpl = modifierList != null && PsiUtilsKt.hasActualModifier(modifierList);
 
-        this.isHeader = modifierList != null && PsiUtilsKt.hasExpectModifier(modifierList) ||
-                        containingDeclaration instanceof ClassDescriptor && ((ClassDescriptor) containingDeclaration).isHeader();
+        this.isExpect = modifierList != null && PsiUtilsKt.hasExpectModifier(modifierList) ||
+                        containingDeclaration instanceof ClassDescriptor && ((ClassDescriptor) containingDeclaration).isExpect();
 
         // Annotation entries are taken from both own annotations (if any) and object literal annotations (if any)
         List<KtAnnotationEntry> annotationEntries = new ArrayList<>();
@@ -498,8 +498,8 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
     }
 
     @Override
-    public boolean isHeader() {
-        return isHeader;
+    public boolean isExpect() {
+        return isExpect;
     }
 
     @Override
@@ -527,7 +527,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
     @Override
     public String toString() {
         // not using DescriptorRenderer to preserve laziness
-        return (isHeader ? "header " : isImpl ? "impl " : "") + "class " + getName().toString();
+        return (isExpect ? "header " : isImpl ? "impl " : "") + "class " + getName().toString();
     }
 
     @Override
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt
index 0ae1f8099be..610178c5f6c 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt
@@ -340,7 +340,7 @@ open class LazyClassMemberScope(
         if (!hasPrimaryConstructor) {
             when (thisDescriptor.kind) {
                 ClassKind.INTERFACE -> return null
-                ClassKind.OBJECT, ClassKind.ENUM_CLASS -> if (thisDescriptor.isHeader) return null
+                ClassKind.OBJECT, ClassKind.ENUM_CLASS -> if (thisDescriptor.isExpect) return null
                 else -> {}
             }
         }
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/DeepCopyIrTreeWithDescriptoros.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/DeepCopyIrTreeWithDescriptoros.kt
index bd4f8c8064a..94373366ad0 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/DeepCopyIrTreeWithDescriptoros.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/DeepCopyIrTreeWithDescriptoros.kt
@@ -277,7 +277,7 @@ class DeepCopyIrTreeWithDescriptors(val targetDescriptor: FunctionDescriptor,
                 /* source                = */ oldDescriptor.source,
                 /* lateInit              = */ oldDescriptor.isLateInit,
                 /* isConst               = */ oldDescriptor.isConst,
-                /* isHeader              = */ oldDescriptor.isHeader,
+                /* isExpect              = */ oldDescriptor.isExpect,
                 /* isImpl                = */ oldDescriptor.isImpl,
                 /* isExternal            = */ oldDescriptor.isExternal,
                 /* isDelegated           = */ oldDescriptor.isDelegated
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/IrBuildUtils.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/IrBuildUtils.kt
index 841b6d11649..916c7f2546d 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/IrBuildUtils.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/IrBuildUtils.kt
@@ -178,7 +178,7 @@ fun BackendContext.createPropertyWithBackingFieldBuilder(startOffset: Int, endOf
                     /* source                = */ SourceElement.NO_SOURCE,
                     /* lateInit              = */ false,
                     /* isConst               = */ false,
-                    /* isHeader              = */ false,
+                    /* isExpect              = */ false,
                     /* isImpl                = */ false,
                     /* isExternal            = */ false,
                     /* isDelegated           = */ false
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
index b2652a8f521..859f7070432 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
@@ -597,7 +597,7 @@ class LocalDeclarationsLowering(val context: BackendContext) : DeclarationContai
                         SourceElement.NO_SOURCE,
                         /* lateInit = */ false,
                         /* isConst = */ false,
-                        /* isHeader = */ false,
+                        /* isExpect = */ false,
                         /* isImpl = */ false,
                         /* isExternal = */ false,
                         /* isDelegated = */ false)
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDescriptorWithExtraFlags.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDescriptorWithExtraFlags.kt
index 5ff2682c347..90e8b5d2d18 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDescriptorWithExtraFlags.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDescriptorWithExtraFlags.kt
@@ -40,11 +40,11 @@ class JvmPropertyDescriptorImpl private constructor(
         source: SourceElement,
         isLateInit: Boolean,
         isConst: Boolean,
-        isHeader: Boolean,
+        isExpect: Boolean,
         isImpl: Boolean
 ) : JvmDescriptorWithExtraFlags, PropertyDescriptorImpl(
         containingDeclaration, original, annotations, modality, visibility, isVar,
-        name, kind, source, isLateInit, isConst, isHeader, isImpl, /* isExternal = */ false, false
+        name, kind, source, isLateInit, isConst, isExpect, isImpl, /* isExternal = */ false, false
 ) {
     override fun createSubstitutedCopy(
             newOwner: DeclarationDescriptor,
@@ -56,7 +56,7 @@ class JvmPropertyDescriptorImpl private constructor(
     ): PropertyDescriptorImpl =
             JvmPropertyDescriptorImpl(
                     newOwner, original, annotations, newModality, newVisibility, extraFlags, isVar, newName, kind,
-                    SourceElement.NO_SOURCE, isLateInit, isConst, isHeader, isImpl
+                    SourceElement.NO_SOURCE, isLateInit, isConst, isExpect, isImpl
             )
 
     companion object {
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/KnownDescriptors.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/KnownDescriptors.kt
index 243e34b8079..f0affdf9b58 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/KnownDescriptors.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/KnownDescriptors.kt
@@ -143,7 +143,7 @@ open class KnownClassDescriptor(
     override fun isCompanionObject(): Boolean = false
     override fun isData(): Boolean = false
     override fun isInner(): Boolean = false
-    override fun isHeader(): Boolean = false
+    override fun isExpect(): Boolean = false
     override fun isImpl(): Boolean = false
     override fun isExternal(): Boolean = false
 
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SharedVariablesManager.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SharedVariablesManager.kt
index 53b621866dc..503e324bc11 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SharedVariablesManager.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SharedVariablesManager.kt
@@ -53,7 +53,7 @@ class JvmSharedVariablesManager(val builtIns: KotlinBuiltIns) : SharedVariablesM
                 PropertyDescriptorImpl.create(
                         refClass, Annotations.EMPTY, Modality.FINAL, Visibilities.PUBLIC, true,
                         Name.identifier("element"), CallableMemberDescriptor.Kind.DECLARATION, SourceElement.NO_SOURCE,
-                        /* lateInit = */ false, /* isConst = */ false, /* isHeader = */ false, /* isImpl = */ false,
+                        /* lateInit = */ false, /* isConst = */ false, /* isExpect = */ false, /* isImpl = */ false,
                         /* isExternal = */ false, /* isDelegated = */ false
                 ).initialize(type, dispatchReceiverParameter = refClass.thisAsReceiverParameter)
     }
@@ -94,7 +94,7 @@ class JvmSharedVariablesManager(val builtIns: KotlinBuiltIns) : SharedVariablesM
                 PropertyDescriptorImpl.create(
                         genericRefClass, Annotations.EMPTY, Modality.FINAL, Visibilities.PUBLIC, true,
                         Name.identifier("element"), CallableMemberDescriptor.Kind.DECLARATION, SourceElement.NO_SOURCE,
-                        /* lateInit = */ false, /* isConst = */ false, /* isHeader = */ false, /* isImpl = */ false,
+                        /* lateInit = */ false, /* isConst = */ false, /* isExpect = */ false, /* isImpl = */ false,
                         /* isExternal = */ false, /* isDelegated = */ false
                 ).initialize(
                         type = builtIns.anyType,
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SpecialDescriptorsFactory.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SpecialDescriptorsFactory.kt
index 3e35213fcec..5efa7053dd6 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SpecialDescriptorsFactory.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SpecialDescriptorsFactory.kt
@@ -130,7 +130,7 @@ class SpecialDescriptorsFactory(
                 Annotations.EMPTY, Modality.FINAL, Visibilities.PUBLIC, false,
                 Name.identifier("INSTANCE"),
                 CallableMemberDescriptor.Kind.SYNTHESIZED, SourceElement.NO_SOURCE, /* lateInit = */ false, /* isConst = */ false,
-                /* isHeader = */ false, /* isImpl = */ false, /* isExternal = */ false, /* isDelegated = */ false
+                /* isExpect = */ false, /* isImpl = */ false, /* isExternal = */ false, /* isDelegated = */ false
         ).initialize(objectDescriptor.defaultType)
     }
 }
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBuiltinFunctionDescriptor.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBuiltinFunctionDescriptor.kt
index 34199ca1419..919e25c4ad0 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBuiltinFunctionDescriptor.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBuiltinFunctionDescriptor.kt
@@ -54,7 +54,7 @@ abstract class IrBuiltinOperatorDescriptorBase(containingDeclaration: Declaratio
     override fun isOperator(): Boolean = false
     override fun isSuspend(): Boolean = false
     override fun isTailrec(): Boolean = false
-    override fun isHeader(): Boolean = false
+    override fun isExpect(): Boolean = false
     override fun isImpl(): Boolean = false
     override fun hasStableParameterNames(): Boolean = true
     override fun hasSynthesizedParameterNames(): Boolean = false
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrDelegateDescriptor.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrDelegateDescriptor.kt
index 5b33a438b42..f0e0a090534 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrDelegateDescriptor.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrDelegateDescriptor.kt
@@ -60,7 +60,7 @@ abstract class IrDelegateDescriptorBase(
         SourceElement.NO_SOURCE,
         /* lateInit = */ false,
         /* isConst = */ false,
-        /* isHeader = */ false,
+        /* isExpect = */ false,
         /* isImpl = */ false,
         /* isExternal = */ false,
         /* isDelegated = */ true
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/FlatSignature.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/FlatSignature.kt
index 9aee2f24071..72703438bc6 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/FlatSignature.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/FlatSignature.kt
@@ -45,7 +45,7 @@ class FlatSignature<out T> private constructor(
         val hasExtensionReceiver: Boolean,
         val hasVarargs: Boolean,
         val numDefaults: Int,
-        val isHeader: Boolean,
+        val isExpect: Boolean,
         val isSyntheticMember: Boolean
 ) {
     val isGeneric = typeParameters.isNotEmpty()
@@ -63,7 +63,7 @@ class FlatSignature<out T> private constructor(
                                  hasExtensionReceiver = false,
                                  hasVarargs = descriptor.valueParameters.any { it.varargElementType != null },
                                  numDefaults = numDefaults,
-                                 isHeader = descriptor is MemberDescriptor && descriptor.isHeader,
+                                 isExpect = descriptor is MemberDescriptor && descriptor.isExpect,
                                  isSyntheticMember = descriptor is SyntheticMemberDescriptor<*>
                                  )
         }
@@ -83,7 +83,7 @@ class FlatSignature<out T> private constructor(
                                  hasExtensionReceiver = extensionReceiverType != null,
                                  hasVarargs = descriptor.valueParameters.any { it.varargElementType != null },
                                  numDefaults = numDefaults,
-                                 isHeader = descriptor is MemberDescriptor && descriptor.isHeader,
+                                 isExpect = descriptor is MemberDescriptor && descriptor.isExpect,
                                  isSyntheticMember = descriptor is SyntheticMemberDescriptor<*>
             )
         }
@@ -100,7 +100,7 @@ class FlatSignature<out T> private constructor(
                               hasExtensionReceiver = false,
                               hasVarargs = descriptor.valueParameters.any { it.varargElementType != null },
                               numDefaults = descriptor.valueParameters.count { it.hasDefaultValue() },
-                              isHeader = descriptor is MemberDescriptor && descriptor.isHeader,
+                              isExpect = descriptor is MemberDescriptor && descriptor.isExpect,
                               isSyntheticMember = descriptor is SyntheticMemberDescriptor<*>
                 )
 
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/OverloadingConflictResolver.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/OverloadingConflictResolver.kt
index 068f0753c28..c2d35477487 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/OverloadingConflictResolver.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/OverloadingConflictResolver.kt
@@ -263,8 +263,8 @@ open class OverloadingConflictResolver<C : Any>(
             if (isGeneric1 && isGeneric2) return false
         }
 
-        if (!call1.isHeader && call2.isHeader) return true
-        if (call1.isHeader && !call2.isHeader) return false
+        if (!call1.isExpect && call2.isExpect) return true
+        if (call1.isExpect && !call2.isExpect) return false
 
         return createEmptyConstraintSystem().isSignatureNotLessSpecific(call1, call2, SpecificityComparisonWithNumerics, specificityComparator)
     }
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
index 5e98edefcf8..91f04a84790 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
@@ -66,7 +66,7 @@ class DescriptorSerializer private constructor(
         val flags = Flags.getClassFlags(
                 hasAnnotations(classDescriptor), classDescriptor.visibility, classDescriptor.modality, classDescriptor.kind,
                 classDescriptor.isInner, classDescriptor.isCompanionObject, classDescriptor.isData, classDescriptor.isExternal,
-                classDescriptor.isHeader
+                classDescriptor.isExpect
         )
         if (flags != builder.flags) {
             builder.flags = flags
@@ -187,7 +187,7 @@ class DescriptorSerializer private constructor(
         val flags = Flags.getPropertyFlags(
                 hasAnnotations, descriptor.visibility, descriptor.modality, descriptor.kind, descriptor.isVar,
                 hasGetter, hasSetter, hasConstant, descriptor.isConst, descriptor.isLateInit, descriptor.isExternal,
-                @Suppress("DEPRECATION") descriptor.isDelegated, descriptor.isHeader
+                @Suppress("DEPRECATION") descriptor.isDelegated, descriptor.isExpect
         )
         if (flags != builder.flags) {
             builder.flags = flags
@@ -233,7 +233,7 @@ class DescriptorSerializer private constructor(
         val flags = Flags.getFunctionFlags(
                 hasAnnotations(descriptor), descriptor.visibility, descriptor.modality, descriptor.kind, descriptor.isOperator,
                 descriptor.isInfix, descriptor.isInline, descriptor.isTailrec, descriptor.isExternal, descriptor.isSuspend,
-                descriptor.isHeader
+                descriptor.isExpect
         )
         if (flags != builder.flags) {
             builder.flags = flags
diff --git a/compiler/tests-common/org/jetbrains/kotlin/test/util/RecursiveDescriptorComparator.java b/compiler/tests-common/org/jetbrains/kotlin/test/util/RecursiveDescriptorComparator.java
index 95894677274..04f3cba3ab2 100644
--- a/compiler/tests-common/org/jetbrains/kotlin/test/util/RecursiveDescriptorComparator.java
+++ b/compiler/tests-common/org/jetbrains/kotlin/test/util/RecursiveDescriptorComparator.java
@@ -195,7 +195,7 @@ public class RecursiveDescriptorComparator {
         }
 
         // 'header' declarations do not belong to the platform-specific module, even though they participate in the analysis
-        if (descriptor instanceof MemberDescriptor && ((MemberDescriptor) descriptor).isHeader() &&
+        if (descriptor instanceof MemberDescriptor && ((MemberDescriptor) descriptor).isExpect() &&
             module.getCapability(MultiTargetPlatform.CAPABILITY) != MultiTargetPlatform.Common.INSTANCE) return false;
 
         return module.equals(DescriptorUtils.getContainingModule(descriptor));
diff --git a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt
index b36671ebf5c..10ef271c5a2 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt
@@ -102,7 +102,7 @@ class LazyJavaClassDescriptor(
     override fun isInner() = isInner
     override fun isData() = false
     override fun isCompanionObject() = false
-    override fun isHeader() = false
+    override fun isExpect() = false
     override fun isImpl() = false
 
     private val typeConstructor = LazyJavaClassTypeConstructor()
diff --git a/core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionClassDescriptor.kt b/core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionClassDescriptor.kt
index 116f6a0f1d1..17ab9416851 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionClassDescriptor.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionClassDescriptor.kt
@@ -100,7 +100,7 @@ class FunctionClassDescriptor(
     override fun isCompanionObject() = false
     override fun isInner() = false
     override fun isData() = false
-    override fun isHeader() = false
+    override fun isExpect() = false
     override fun isImpl() = false
     override fun isExternal() = false
     override val annotations: Annotations get() = Annotations.EMPTY
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/MemberDescriptor.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/MemberDescriptor.java
index dde19d00f72..8317db1b710 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/MemberDescriptor.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/MemberDescriptor.java
@@ -26,7 +26,7 @@ public interface MemberDescriptor extends DeclarationDescriptorNonRoot, Declarat
     @NotNull
     Visibility getVisibility();
 
-    boolean isHeader();
+    boolean isExpect();
 
     boolean isImpl();
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/NotFoundClasses.kt b/core/descriptors/src/org/jetbrains/kotlin/descriptors/NotFoundClasses.kt
index f9149fdf5ac..103a4a19164 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/NotFoundClasses.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/NotFoundClasses.kt
@@ -78,7 +78,7 @@ class NotFoundClasses(private val storageManager: StorageManager, private val mo
 
         override fun isCompanionObject() = false
         override fun isData() = false
-        override fun isHeader() = false
+        override fun isExpect() = false
         override fun isImpl() = false
         override fun isExternal() = false
         override val annotations: Annotations get() = Annotations.EMPTY
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractTypeAliasDescriptor.kt b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractTypeAliasDescriptor.kt
index 3832ba10b9b..f0fcfdeb707 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractTypeAliasDescriptor.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractTypeAliasDescriptor.kt
@@ -74,7 +74,7 @@ abstract class AbstractTypeAliasDescriptor(
 
     override fun getVisibility() = visibilityImpl
 
-    override fun isHeader(): Boolean = false
+    override fun isExpect(): Boolean = false
 
     override fun isImpl(): Boolean = false
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ClassDescriptorImpl.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ClassDescriptorImpl.java
index 16de14a3132..1316c30af42 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ClassDescriptorImpl.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ClassDescriptorImpl.java
@@ -116,7 +116,7 @@ public class ClassDescriptorImpl extends ClassDescriptorBase {
     }
 
     @Override
-    public boolean isHeader() {
+    public boolean isExpect() {
         return false;
     }
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java
index bfdb768a412..1763a8de3d2 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java
@@ -155,7 +155,7 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
     }
 
     @Override
-    public boolean isHeader() {
+    public boolean isExpect() {
         return false;
     }
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java
index 98748da7941..834f658708f 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java
@@ -43,7 +43,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     private boolean isExternal = false;
     private boolean isInline = false;
     private boolean isTailrec = false;
-    private boolean isHeader = false;
+    private boolean isExpect = false;
     private boolean isImpl = false;
     // Difference between these hidden kinds:
     // 1. isHiddenToOvercomeSignatureClash prohibit calling such functions even in super-call context
@@ -136,8 +136,8 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         this.isTailrec = isTailrec;
     }
 
-    public void setHeader(boolean isHeader) {
-        this.isHeader = isHeader;
+    public void setExpect(boolean isExpect) {
+        this.isExpect = isExpect;
     }
 
     public void setImpl(boolean isImpl) {
@@ -258,8 +258,8 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     }
 
     @Override
-    public boolean isHeader() {
-        return isHeader;
+    public boolean isExpect() {
+        return isExpect;
     }
 
     @Override
@@ -664,7 +664,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         substitutedDescriptor.setInline(isInline);
         substitutedDescriptor.setTailrec(isTailrec);
         substitutedDescriptor.setSuspend(isSuspend);
-        substitutedDescriptor.setHeader(isHeader);
+        substitutedDescriptor.setExpect(isExpect);
         substitutedDescriptor.setImpl(isImpl);
         substitutedDescriptor.setHasStableParameterNames(hasStableParameterNames);
         substitutedDescriptor.setHiddenToOvercomeSignatureClash(configuration.isHiddenToOvercomeSignatureClash);
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/LazySubstitutingClassDescriptor.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/LazySubstitutingClassDescriptor.java
index e6b197721a5..07db5a36db4 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/LazySubstitutingClassDescriptor.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/LazySubstitutingClassDescriptor.java
@@ -227,8 +227,8 @@ public class LazySubstitutingClassDescriptor implements ClassDescriptor {
     }
 
     @Override
-    public boolean isHeader() {
-        return original.isHeader();
+    public boolean isExpect() {
+        return original.isExpect();
     }
 
     @Override
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/MutableClassDescriptor.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/MutableClassDescriptor.java
index 7e8038ebe35..014bfde5c5e 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/MutableClassDescriptor.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/MutableClassDescriptor.java
@@ -107,7 +107,7 @@ public class MutableClassDescriptor extends ClassDescriptorBase {
     }
 
     @Override
-    public boolean isHeader() {
+    public boolean isExpect() {
         return false;
     }
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyAccessorDescriptorImpl.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyAccessorDescriptorImpl.java
index d5ed8135187..9a3efbb72fb 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyAccessorDescriptorImpl.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyAccessorDescriptorImpl.java
@@ -103,7 +103,7 @@ public abstract class PropertyAccessorDescriptorImpl extends DeclarationDescript
     }
 
     @Override
-    public boolean isHeader() {
+    public boolean isExpect() {
         return false;
     }
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyDescriptorImpl.java b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyDescriptorImpl.java
index f9ef7d61ea9..0ce774a1e52 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyDescriptorImpl.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyDescriptorImpl.java
@@ -42,7 +42,7 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
     private final Kind kind;
     private final boolean lateInit;
     private final boolean isConst;
-    private final boolean isHeader;
+    private final boolean isExpect;
     private final boolean isImpl;
     private final boolean isExternal;
     private final boolean isDelegated;
@@ -66,7 +66,7 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
             @NotNull SourceElement source,
             boolean lateInit,
             boolean isConst,
-            boolean isHeader,
+            boolean isExpect,
             boolean isImpl,
             boolean isExternal,
             boolean isDelegated
@@ -78,7 +78,7 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
         this.kind = kind;
         this.lateInit = lateInit;
         this.isConst = isConst;
-        this.isHeader = isHeader;
+        this.isExpect = isExpect;
         this.isImpl = isImpl;
         this.isExternal = isExternal;
         this.isDelegated = isDelegated;
@@ -96,14 +96,14 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
             @NotNull SourceElement source,
             boolean lateInit,
             boolean isConst,
-            boolean isHeader,
+            boolean isExpect,
             boolean isImpl,
             boolean isExternal,
             boolean isDelegated
     ) {
         return new PropertyDescriptorImpl(containingDeclaration, null, annotations,
                                           modality, visibility, isVar, name, kind, source, lateInit, isConst,
-                                          isHeader, isImpl, isExternal, isDelegated);
+                                          isExpect, isImpl, isExternal, isDelegated);
     }
 
     public void setType(
@@ -458,7 +458,7 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
     ) {
         return new PropertyDescriptorImpl(
                 newOwner, original, getAnnotations(), newModality, newVisibility, isVar(), newName, kind, SourceElement.NO_SOURCE,
-                isLateInit(), isConst(), isHeader(), isImpl(), isExternal(), isDelegated()
+                isLateInit(), isConst(), isExpect(), isImpl(), isExternal(), isDelegated()
         );
     }
 
@@ -480,8 +480,8 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
     }
 
     @Override
-    public boolean isHeader() {
-        return isHeader;
+    public boolean isExpect() {
+        return isExpect;
     }
 
     @Override
diff --git a/core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererImpl.kt b/core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererImpl.kt
index fa8c45db956..b71bd55abab 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererImpl.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererImpl.kt
@@ -509,7 +509,7 @@ internal class DescriptorRendererImpl(
 
     private fun renderMemberModifiers(descriptor: MemberDescriptor, builder: StringBuilder) {
         renderModifier(builder, descriptor.isExternal, "external")
-        renderModifier(builder, DescriptorRendererModifier.HEADER in modifiers && descriptor.isHeader, "header")
+        renderModifier(builder, DescriptorRendererModifier.HEADER in modifiers && descriptor.isExpect, "header")
         renderModifier(builder, DescriptorRendererModifier.IMPL in modifiers && descriptor.isImpl, "impl")
     }
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/util/scopeUtils.kt b/core/descriptors/src/org/jetbrains/kotlin/util/scopeUtils.kt
index 20c89c1fc73..3d14118e752 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/util/scopeUtils.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/util/scopeUtils.kt
@@ -78,7 +78,7 @@ inline fun <Scope, T : ClassifierDescriptor> getFirstClassifierDiscriminateHeade
     for (scope in scopes) {
         val newResult = callback(scope)
         if (newResult != null) {
-            if (newResult is ClassifierDescriptorWithTypeParameters && newResult.isHeader) {
+            if (newResult is ClassifierDescriptorWithTypeParameters && newResult.isExpect) {
                 if (result == null) result = newResult
             }
             // this class is Impl or usual class
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/Flags.java b/core/deserialization/src/org/jetbrains/kotlin/serialization/Flags.java
index 2f68c9a53c3..4efb94d69d1 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/Flags.java
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/Flags.java
@@ -98,7 +98,7 @@ public class Flags {
             boolean isCompanionObject,
             boolean isData,
             boolean isExternal,
-            boolean isHeader
+            boolean isExpect
     ) {
         return HAS_ANNOTATIONS.toFlags(hasAnnotations)
                | MODALITY.toFlags(modality(modality))
@@ -107,7 +107,7 @@ public class Flags {
                | IS_INNER.toFlags(inner)
                | IS_DATA.toFlags(isData)
                | IS_EXTERNAL_CLASS.toFlags(isExternal)
-               | IS_HEADER_CLASS.toFlags(isHeader)
+               | IS_HEADER_CLASS.toFlags(isExpect)
                ;
     }
 
@@ -153,7 +153,7 @@ public class Flags {
             boolean isTailrec,
             boolean isExternal,
             boolean isSuspend,
-            boolean isHeader
+            boolean isExpect
     ) {
         return HAS_ANNOTATIONS.toFlags(hasAnnotations)
                | VISIBILITY.toFlags(visibility(visibility))
@@ -165,7 +165,7 @@ public class Flags {
                | IS_TAILREC.toFlags(isTailrec)
                | IS_EXTERNAL_FUNCTION.toFlags(isExternal)
                | IS_SUSPEND.toFlags(isSuspend)
-               | IS_HEADER_FUNCTION.toFlags(isHeader)
+               | IS_HEADER_FUNCTION.toFlags(isExpect)
                 ;
     }
 
@@ -182,7 +182,7 @@ public class Flags {
             boolean lateInit,
             boolean isExternal,
             boolean isDelegated,
-            boolean isHeader
+            boolean isExpect
     ) {
         return HAS_ANNOTATIONS.toFlags(hasAnnotations)
                | VISIBILITY.toFlags(visibility(visibility))
@@ -196,7 +196,7 @@ public class Flags {
                | HAS_CONSTANT.toFlags(hasConstant)
                | IS_EXTERNAL_PROPERTY.toFlags(isExternal)
                | IS_DELEGATED.toFlags(isDelegated)
-               | IS_HEADER_PROPERTY.toFlags(isHeader)
+               | IS_HEADER_PROPERTY.toFlags(isExpect)
                 ;
     }
 
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/MemberDeserializer.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/MemberDeserializer.kt
index 7a7bd6b68ce..eb3459f7c4d 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/MemberDeserializer.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/MemberDeserializer.kt
@@ -175,7 +175,7 @@ class MemberDeserializer(private val c: DeserializationContext) {
         function.isInline = Flags.IS_INLINE.get(flags)
         function.isTailrec = Flags.IS_TAILREC.get(flags)
         function.isSuspend = Flags.IS_SUSPEND.get(flags)
-        function.isHeader = Flags.IS_HEADER_FUNCTION.get(flags)
+        function.isExpect = Flags.IS_HEADER_FUNCTION.get(flags)
         return function
     }
 
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt
index 1dfde2a5058..fc7b9d27204 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt
@@ -98,7 +98,7 @@ class DeserializedClassDescriptor(
 
     override fun isData() = Flags.IS_DATA.get(classProto.flags)
 
-    override fun isHeader() = Flags.IS_HEADER_CLASS.get(classProto.flags)
+    override fun isExpect() = Flags.IS_HEADER_CLASS.get(classProto.flags)
 
     override fun isImpl() = false
 
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedMemberDescriptor.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedMemberDescriptor.kt
index 8ec2ac787f8..2ed24264cee 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedMemberDescriptor.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedMemberDescriptor.kt
@@ -16,8 +16,6 @@
 
 package org.jetbrains.kotlin.serialization.deserialization.descriptors
 
-import org.jetbrains.annotations.NotNull
-import org.jetbrains.annotations.Nullable
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.*
@@ -106,7 +104,7 @@ class DeserializedPropertyDescriptor(
         isConst: Boolean,
         isExternal: Boolean,
         isDelegated: Boolean,
-        isHeader: Boolean,
+        isExpect: Boolean,
         override val proto: ProtoBuf.Property,
         override val nameResolver: NameResolver,
         override val typeTable: TypeTable,
@@ -114,7 +112,7 @@ class DeserializedPropertyDescriptor(
         override val containerSource: DeserializedContainerSource?
 ) : DeserializedCallableMemberDescriptor, PropertyDescriptorImpl(
         containingDeclaration, original, annotations, modality, visibility, isVar, name, kind, SourceElement.NO_SOURCE,
-        isLateInit, isConst, isHeader, false, isExternal, isDelegated
+        isLateInit, isConst, isExpect, false, isExternal, isDelegated
 ) {
     override fun createSubstitutedCopy(
             newOwner: DeclarationDescriptor,
@@ -126,7 +124,7 @@ class DeserializedPropertyDescriptor(
     ): PropertyDescriptorImpl {
         return DeserializedPropertyDescriptor(
                 newOwner, original, annotations, newModality, newVisibility, isVar, newName, kind, isLateInit, isConst, isExternal,
-                @Suppress("DEPRECATION") isDelegated, isHeader, proto, nameResolver, typeTable, sinceKotlinInfoTable, containerSource
+                @Suppress("DEPRECATION") isDelegated, isExpect, proto, nameResolver, typeTable, sinceKotlinInfoTable, containerSource
         )
     }
 
diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/PlatformHeaderAnnotator.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/PlatformHeaderAnnotator.kt
index 17331850579..d6df90b5493 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/PlatformHeaderAnnotator.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/PlatformHeaderAnnotator.kt
@@ -56,7 +56,7 @@ val ModuleDescriptor.allImplementingCompatibleModules
 class PlatformHeaderAnnotator : Annotator {
     override fun annotate(element: PsiElement, holder: AnnotationHolder) {
         val declaration = element as? KtDeclaration ?: return
-        if (!isHeaderDeclaration(declaration)) return
+        if (!isExpectDeclaration(declaration)) return
 
         if (TargetPlatformDetector.getPlatform(declaration.containingKtFile) !is TargetPlatform.Common) return
 
@@ -64,7 +64,7 @@ class PlatformHeaderAnnotator : Annotator {
         if (implementingModules.isEmpty()) return
 
         val descriptor = declaration.toDescriptor() as? MemberDescriptor ?: return
-        if (!descriptor.isHeader) return
+        if (!descriptor.isExpect) return
 
         val trace = BindingTraceContext()
         for (module in implementingModules) {
@@ -80,7 +80,7 @@ class PlatformHeaderAnnotator : Annotator {
         KotlinPsiChecker().annotateElement(declaration, holder, SimpleDiagnostics(filteredList))
     }
 
-    private fun isHeaderDeclaration(declaration: KtDeclaration): Boolean {
+    private fun isExpectDeclaration(declaration: KtDeclaration): Boolean {
         return declaration.hasExpectModifier() ||
                declaration is KtClassOrObject && KtPsiUtil.getOutermostClassOrObject(declaration)?.hasExpectModifier() == true
     }
diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/overrideImplement/OverrideMemberChooserObject.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/overrideImplement/OverrideMemberChooserObject.kt
index 4c116a42153..2e0cb9bb456 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/overrideImplement/OverrideMemberChooserObject.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/overrideImplement/OverrideMemberChooserObject.kt
@@ -148,7 +148,7 @@ private val OVERRIDE_RENDERER = DescriptorRenderer.withOptions {
 private fun PropertyDescriptor.wrap(): PropertyDescriptor {
     val delegate = copy(containingDeclaration, Modality.OPEN, visibility, kind, true) as PropertyDescriptor
     val newDescriptor = object : PropertyDescriptor by delegate {
-        override fun isHeader() = false
+        override fun isExpect() = false
     }
     newDescriptor.setSingleOverridden(this)
     return newDescriptor
@@ -156,7 +156,7 @@ private fun PropertyDescriptor.wrap(): PropertyDescriptor {
 
 private fun FunctionDescriptor.wrap(): FunctionDescriptor {
     return object : FunctionDescriptor by this {
-        override fun isHeader() = false
+        override fun isExpect() = false
         override fun getModality() = Modality.OPEN
         override fun getReturnType() = this@wrap.returnType?.approximateFlexibleTypes(preferNotNull = true, preferStarForRaw = true)
         override fun getOverriddenDescriptors() = listOf(this@wrap)
diff --git a/idea/idea-jvm/src/org/jetbrains/kotlin/idea/run/KotlinMultiplatformJUnitRecognizer.kt b/idea/idea-jvm/src/org/jetbrains/kotlin/idea/run/KotlinMultiplatformJUnitRecognizer.kt
index 8f9b365c42c..d271f3381cf 100644
--- a/idea/idea-jvm/src/org/jetbrains/kotlin/idea/run/KotlinMultiplatformJUnitRecognizer.kt
+++ b/idea/idea-jvm/src/org/jetbrains/kotlin/idea/run/KotlinMultiplatformJUnitRecognizer.kt
@@ -46,14 +46,14 @@ class KotlinMultiplatformJUnitRecognizer : JUnitRecognizer() {
 
         val bindingContext = origin.analyze(BodyResolveMode.PARTIAL)
         val methodDescriptor = bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, origin] ?: return false
-        return methodDescriptor.annotations.getAllAnnotations().any { it.isHeaderOfAnnotation("org.junit.Test", implModules) }
+        return methodDescriptor.annotations.getAllAnnotations().any { it.isExpectOfAnnotation("org.junit.Test", implModules) }
 
     }
 }
 
-private fun AnnotationWithTarget.isHeaderOfAnnotation(fqName: String, implModules: Collection<ModuleDescriptor>): Boolean {
+private fun AnnotationWithTarget.isExpectOfAnnotation(fqName: String, implModules: Collection<ModuleDescriptor>): Boolean {
     val annotationClass = annotation.type.constructor.declarationDescriptor as? ClassifierDescriptorWithTypeParameters ?: return false
-    if (!annotationClass.isHeader) return false
+    if (!annotationClass.isExpect) return false
 
     return implModules
         .any { module ->
diff --git a/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/DeclaredHeaderMarker.kt b/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/DeclaredHeaderMarker.kt
index 1874d308368..07d22ba1da0 100644
--- a/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/DeclaredHeaderMarker.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/DeclaredHeaderMarker.kt
@@ -65,13 +65,13 @@ internal fun KtDeclaration.headerDeclarationIfAny(): KtDeclaration? {
     return DescriptorToSourceUtils.descriptorToDeclaration(headerDescriptor) as? KtDeclaration
 }
 
-internal fun KtDeclaration.isHeaderOrHeaderClassMember() =
+internal fun KtDeclaration.isExpectOrExpectClassMember() =
         hasExpectModifier() || (containingClassOrObject?.hasExpectModifier() ?: false)
 
 internal fun DeclarationDescriptor.liftToHeader(): DeclarationDescriptor? {
     if (this is MemberDescriptor) {
         return when {
-            isHeader -> this
+            isExpect -> this
             isImpl -> headerDescriptor()
             else -> null
         }
diff --git a/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/ImplementedHeaderMarker.kt b/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/ImplementedHeaderMarker.kt
index 3f2e8deeb69..18f8a018782 100644
--- a/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/ImplementedHeaderMarker.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/highlighter/markers/ImplementedHeaderMarker.kt
@@ -72,7 +72,7 @@ fun navigateToPlatformImplementation(e: MouseEvent?, declaration: KtDeclaration)
 
 private fun DeclarationDescriptor.headerImplementations(): Collection<DeclarationDescriptor> {
     if (this is MemberDescriptor) {
-        if (!this.isHeader) return emptyList()
+        if (!this.isExpect) return emptyList()
 
         return module.allImplementingCompatibleModules.flatMap { it.implementationsOf(this) }
     }
diff --git a/idea/src/org/jetbrains/kotlin/idea/intentions/AddAccessorIntentions.kt b/idea/src/org/jetbrains/kotlin/idea/intentions/AddAccessorIntentions.kt
index 292c5a8dcad..1199b8003f0 100644
--- a/idea/src/org/jetbrains/kotlin/idea/intentions/AddAccessorIntentions.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/intentions/AddAccessorIntentions.kt
@@ -38,7 +38,7 @@ abstract class AbstractAddAccessorsIntention(
             return null
         }
         val descriptor = element.resolveToDescriptorIfAny() as? CallableMemberDescriptor ?: return null
-        if (descriptor.isHeader) return null
+        if (descriptor.isExpect) return null
 
         if (addSetter && (!element.isVar || element.setter != null)) return null
         if (addGetter && element.getter != null) return null
diff --git a/idea/src/org/jetbrains/kotlin/idea/intentions/declarations/ConvertMemberToExtensionIntention.kt b/idea/src/org/jetbrains/kotlin/idea/intentions/declarations/ConvertMemberToExtensionIntention.kt
index 6a8201dc668..f29f3e55477 100644
--- a/idea/src/org/jetbrains/kotlin/idea/intentions/declarations/ConvertMemberToExtensionIntention.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/intentions/declarations/ConvertMemberToExtensionIntention.kt
@@ -34,7 +34,7 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.unsafeResolveToDescriptor
 import org.jetbrains.kotlin.idea.core.*
 import org.jetbrains.kotlin.idea.highlighter.markers.headerImplementations
-import org.jetbrains.kotlin.idea.highlighter.markers.isHeaderOrHeaderClassMember
+import org.jetbrains.kotlin.idea.highlighter.markers.isExpectOrExpectClassMember
 import org.jetbrains.kotlin.idea.highlighter.markers.liftToHeader
 import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
 import org.jetbrains.kotlin.idea.quickfix.createFromUsage.callableBuilder.getReturnTypeReference
@@ -111,7 +111,7 @@ class ConvertMemberToExtensionIntention : SelfTargetingRangeIntention<KtCallable
         val descriptor = element.unsafeResolveToDescriptor()
         val containingClass = descriptor.containingDeclaration as ClassDescriptor
 
-        val isEffectiveHeader = allowHeader && element.isHeaderOrHeaderClassMember()
+        val isEffectiveHeader = allowHeader && element.isExpectOrExpectClassMember()
 
         val file = element.containingKtFile
         val project = file.project
diff --git a/idea/src/org/jetbrains/kotlin/idea/refactoring/CallableRefactoring.kt b/idea/src/org/jetbrains/kotlin/idea/refactoring/CallableRefactoring.kt
index 7a5b7c0f052..fc07381921d 100644
--- a/idea/src/org/jetbrains/kotlin/idea/refactoring/CallableRefactoring.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/refactoring/CallableRefactoring.kt
@@ -36,7 +36,7 @@ import org.jetbrains.kotlin.idea.codeInsight.DescriptorToSourceUtilsIde
 import org.jetbrains.kotlin.idea.core.getDeepestSuperDeclarations
 import org.jetbrains.kotlin.idea.core.getDirectlyOverriddenDeclarations
 import org.jetbrains.kotlin.idea.highlighter.markers.headerImplementations
-import org.jetbrains.kotlin.idea.highlighter.markers.isHeaderOrHeaderClassMember
+import org.jetbrains.kotlin.idea.highlighter.markers.isExpectOrExpectClassMember
 import org.jetbrains.kotlin.idea.highlighter.markers.liftToHeader
 import org.jetbrains.kotlin.idea.util.getResolutionScope
 import org.jetbrains.kotlin.psi.KtBlockExpression
@@ -184,7 +184,7 @@ abstract class CallableRefactoring<out T: CallableDescriptor>(
 fun getAffectedCallables(project: Project, descriptorsForChange: Collection<CallableDescriptor>): List<PsiElement> {
     val baseCallables = descriptorsForChange.mapNotNull { DescriptorToSourceUtilsIde.getAnyDeclaration(project, it) }
     return baseCallables + baseCallables.flatMapTo(HashSet<PsiElement>()) { callable ->
-        if (callable is KtDeclaration && callable.isHeaderOrHeaderClassMember()) {
+        if (callable is KtDeclaration && callable.isExpectOrExpectClassMember()) {
             callable.headerImplementations()
         }
         else {
diff --git a/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureData.kt b/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureData.kt
index e15698dfd6a..574c2b35073 100644
--- a/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureData.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureData.kt
@@ -29,7 +29,7 @@ import org.jetbrains.kotlin.descriptors.impl.AnonymousFunctionDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.unsafeResolveToDescriptor
 import org.jetbrains.kotlin.idea.codeInsight.DescriptorToSourceUtilsIde
 import org.jetbrains.kotlin.idea.highlighter.markers.headerImplementations
-import org.jetbrains.kotlin.idea.highlighter.markers.isHeaderOrHeaderClassMember
+import org.jetbrains.kotlin.idea.highlighter.markers.isExpectOrExpectClassMember
 import org.jetbrains.kotlin.idea.refactoring.changeSignature.usages.KotlinCallableDefinitionUsage
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
 import org.jetbrains.kotlin.psi.*
@@ -98,7 +98,7 @@ class KotlinChangeSignatureData(
         primaryCallables + primaryCallables.flatMapTo(HashSet<UsageInfo>()) { primaryFunction ->
             val primaryDeclaration = primaryFunction.declaration as? KtDeclaration ?: return@flatMapTo emptyList()
 
-            if (primaryDeclaration.isHeaderOrHeaderClassMember()) {
+            if (primaryDeclaration.isExpectOrExpectClassMember()) {
                 return@flatMapTo primaryDeclaration.headerImplementations().mapNotNull {
                     val descriptor = it.unsafeResolveToDescriptor()
                     val callableDescriptor = when (descriptor) {
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
index f34d8ff3984..6b032b0f4c7 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
@@ -69,7 +69,7 @@ class JsNameClashChecker : SimpleDeclarationChecker {
             if (existing != null &&
                 existing != descriptor &&
                 existing.isImpl == descriptor.isImpl &&
-                existing.isHeader == descriptor.isHeader &&
+                existing.isExpect == descriptor.isExpect &&
                 !bindingContext.isCommonDiagnosticReported(declaration)
             ) {
                 diagnosticHolder.report(ErrorsJs.JS_NAME_CLASH.on(declaration, name, existing))
@@ -112,8 +112,8 @@ class JsNameClashChecker : SimpleDeclarationChecker {
     private val DeclarationDescriptor.isImpl: Boolean
         get() = this is MemberDescriptor && this.isImpl
 
-    private val DeclarationDescriptor.isHeader: Boolean
-        get() = this is MemberDescriptor && this.isHeader
+    private val DeclarationDescriptor.isExpect: Boolean
+        get() = this is MemberDescriptor && this.isExpect
 
     private fun isFakeOverridingNative(descriptor: CallableMemberDescriptor): Boolean {
         return descriptor.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE &&
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/translate/utils/AnnotationsUtils.java b/js/js.frontend/src/org/jetbrains/kotlin/js/translate/utils/AnnotationsUtils.java
index 7902c2d144c..07a0cf2e8ed 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/translate/utils/AnnotationsUtils.java
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/translate/utils/AnnotationsUtils.java
@@ -163,7 +163,7 @@ public final class AnnotationsUtils {
     }
 
     public static boolean isPredefinedObject(@NotNull DeclarationDescriptor descriptor) {
-        if (descriptor instanceof MemberDescriptor && ((MemberDescriptor) descriptor).isHeader()) return true;
+        if (descriptor instanceof MemberDescriptor && ((MemberDescriptor) descriptor).isExpect()) return true;
         if (isEffectivelyExternalMember(descriptor)) return true;
 
         for (PredefinedAnnotation annotation : PredefinedAnnotation.values()) {
diff --git a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
index 25874d3f6a6..8fa0d7013f2 100644
--- a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
+++ b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
@@ -130,7 +130,7 @@ object KotlinJavascriptSerializationUtil {
         val builder = ProtoBuf.PackageFragment.newBuilder()
 
         // TODO: ModuleDescriptor should be able to return the package only with the contents of that module, without dependencies
-        val skip: (DeclarationDescriptor) -> Boolean = { DescriptorUtils.getContainingModule(it) != module || (it is MemberDescriptor && it.isHeader) }
+        val skip: (DeclarationDescriptor) -> Boolean = { DescriptorUtils.getContainingModule(it) != module || (it is MemberDescriptor && it.isExpect) }
 
         val fileRegistry = KotlinFileRegistry()
         val serializerExtension = KotlinJavascriptSerializerExtension(fileRegistry)
diff --git a/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/synthetic/res/syntheticDescriptorGeneration.kt b/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/synthetic/res/syntheticDescriptorGeneration.kt
index 8ffe321a59d..fdfa3cbcb36 100644
--- a/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/synthetic/res/syntheticDescriptorGeneration.kt
+++ b/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/synthetic/res/syntheticDescriptorGeneration.kt
@@ -104,7 +104,7 @@ private fun genProperty(
             sourceElement,
             /* lateInit = */ false,
             /* isConst = */ false,
-            /* isHeader = */ false,
+            /* isExpect = */ false,
             /* isImpl = */ false,
             /* isExternal = */ false,
             /* isDelegated = */ false