diff --git a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
index 9f10dd207cf..3fc907f5ed1 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
@@ -195,7 +195,7 @@ public class DefaultErrorMessages {
                 case INVOKE_ON_FUNCTION_TYPE:
                     return "function types";
                 case EXPECTED_CLASS_MEMBER:
-                    return "members of header classes";
+                    return "members of expected classes";
                 default:
                     throw new AssertionError(target);
             }
@@ -262,26 +262,26 @@ public class DefaultErrorMessages {
         MAP.put(MULTIPLE_VARARG_PARAMETERS, "Multiple vararg-parameters are prohibited");
         MAP.put(FORBIDDEN_VARARG_PARAMETER_TYPE, "Forbidden vararg parameter type: {0}", RENDER_TYPE);
 
-        MAP.put(EXPECTED_DECLARATION_WITH_BODY, "Header declaration must not have a body");
-        MAP.put(EXPECTED_DECLARATION_WITH_DEFAULT_PARAMETER, "Header declaration cannot have parameters with default values");
-        MAP.put(EXPECTED_CLASS_CONSTRUCTOR_DELEGATION_CALL, "Explicit delegation call for constructor of a header class is not allowed");
-        MAP.put(EXPECTED_CLASS_CONSTRUCTOR_PROPERTY_PARAMETER, "Header class constructor cannot have a property parameter");
-        MAP.put(EXPECTED_ENUM_CONSTRUCTOR, "Header enum class cannot have a constructor");
-        MAP.put(EXPECTED_ENUM_ENTRY_WITH_BODY, "Header enum entry cannot have a body");
-        MAP.put(EXPECTED_PROPERTY_INITIALIZER, "Header property cannot have an initializer");
+        MAP.put(EXPECTED_DECLARATION_WITH_BODY, "Expected declaration must not have a body");
+        MAP.put(EXPECTED_DECLARATION_WITH_DEFAULT_PARAMETER, "Expected declaration cannot have parameters with default values");
+        MAP.put(EXPECTED_CLASS_CONSTRUCTOR_DELEGATION_CALL, "Explicit delegation call for constructor of an expected class is not allowed");
+        MAP.put(EXPECTED_CLASS_CONSTRUCTOR_PROPERTY_PARAMETER, "Expected class constructor cannot have a property parameter");
+        MAP.put(EXPECTED_ENUM_CONSTRUCTOR, "Expected enum class cannot have a constructor");
+        MAP.put(EXPECTED_ENUM_ENTRY_WITH_BODY, "Expected enum entry cannot have a body");
+        MAP.put(EXPECTED_PROPERTY_INITIALIZER, "Expected property cannot have an initializer");
 
-        MAP.put(ACTUAL_TYPE_ALIAS_NOT_TO_CLASS, "Right-hand side of 'impl' type alias should be a class, not another type alias");
+        MAP.put(ACTUAL_TYPE_ALIAS_NOT_TO_CLASS, "Right-hand side of actual type alias should be a class, not another type alias");
         MAP.put(ACTUAL_TYPE_ALIAS_TO_CLASS_WITH_DECLARATION_SITE_VARIANCE, "Aliased class should not have type parameters with declaration-site variance");
-        MAP.put(ACTUAL_TYPE_ALIAS_WITH_USE_SITE_VARIANCE, "Right-hand side of 'impl' type alias cannot contain use-site variance or star projections");
-        MAP.put(ACTUAL_TYPE_ALIAS_WITH_COMPLEX_SUBSTITUTION, "Type arguments in the right-hand side of 'impl' type alias should be its type parameters in the same order, e.g. 'impl typealias Foo<A, B> = Bar<A, B>'");
+        MAP.put(ACTUAL_TYPE_ALIAS_WITH_USE_SITE_VARIANCE, "Right-hand side of actual type alias cannot contain use-site variance or star projections");
+        MAP.put(ACTUAL_TYPE_ALIAS_WITH_COMPLEX_SUBSTITUTION, "Type arguments in the right-hand side of actual type alias should be its type parameters in the same order, e.g. 'impl typealias Foo<A, B> = Bar<A, B>'");
 
-        MAP.put(NO_ACTUAL_FOR_EXPECT, "''header'' {0} has no implementation in module{1}{2}", DECLARATION_NAME_WITH_KIND,
+        MAP.put(NO_ACTUAL_FOR_EXPECT, "Expected {0} has no actual in module{1}{2}", DECLARATION_NAME_WITH_KIND,
                 PLATFORM, PlatformIncompatibilityDiagnosticRenderer.TEXT);
-        MAP.put(ACTUAL_WITHOUT_EXPECT, "''impl'' {0} has no corresponding ''header'' declaration{1}", DECLARATION_NAME_WITH_KIND,
+        MAP.put(ACTUAL_WITHOUT_EXPECT, "Actual {0} has no corresponding expected declaration{1}", DECLARATION_NAME_WITH_KIND,
                 PlatformIncompatibilityDiagnosticRenderer.TEXT);
 
-        MAP.put(NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS, "''impl'' class ''{0}'' has no implementation of ''header'' class members:{1}",
-                NAME, IncompatibleHeaderImplClassScopesRenderer.TEXT);
+        MAP.put(NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS, "In class ''{0}'' expected members have no actual ones:{1}",
+                NAME, IncompatibleExpectedActualClassScopesRenderer.TEXT);
         MAP.put(ACTUAL_MISSING, "Declaration should be marked with 'actual' (suppress with -Xno-check-actual)");
 
         MAP.put(PROJECTION_ON_NON_CLASS_TYPE_ARGUMENT, "Projections are not allowed on type arguments of functions and properties");
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/PlatformIncompatibilityDiagnosticRenderer.kt b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/PlatformIncompatibilityDiagnosticRenderer.kt
index 334cccf68a6..3cf85f8c352 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/PlatformIncompatibilityDiagnosticRenderer.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/PlatformIncompatibilityDiagnosticRenderer.kt
@@ -41,7 +41,7 @@ class PlatformIncompatibilityDiagnosticRenderer(
     }
 }
 
-class IncompatibleHeaderImplClassScopesRenderer(
+class IncompatibleExpectedActualClassScopesRenderer(
         private val mode: MultiplatformDiagnosticRenderingMode
 ) : DiagnosticParameterRenderer<List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>> {
     override fun render(
@@ -58,7 +58,7 @@ class IncompatibleHeaderImplClassScopesRenderer(
 
     companion object {
         @JvmField
-        val TEXT = IncompatibleHeaderImplClassScopesRenderer(MultiplatformDiagnosticRenderingMode())
+        val TEXT = IncompatibleExpectedActualClassScopesRenderer(MultiplatformDiagnosticRenderingMode())
     }
 }
 
@@ -101,7 +101,7 @@ private fun StringBuilder.renderIncompatibilityInformation(
 
         if (incompatibility is Incompatible.ClassScopes) {
             append(indent)
-            append("No implementations are found for members listed below:")
+            append("No actuals are found for expected members listed below:")
             mode.newLine(this)
             renderIncompatibleClassScopes(incompatibility.unfulfilled, indent, context, mode)
         }
@@ -109,20 +109,20 @@ private fun StringBuilder.renderIncompatibilityInformation(
 }
 
 private fun StringBuilder.renderIncompatibleClassScopes(
-        unimplemented: List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>,
+        unfulfilled: List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>,
         indent: String,
         context: RenderingContext,
         mode: MultiplatformDiagnosticRenderingMode
 ) {
-    mode.renderList(this, unimplemented.indices.map { index ->
+    mode.renderList(this, unfulfilled.indices.map { index ->
         {
-            val (descriptor, mapping) = unimplemented[index]
+            val (descriptor, mapping) = unfulfilled[index]
             mode.renderDescriptor(this, descriptor, context, indent)
             if (mapping.isNotEmpty()) {
                 mode.newLine(this)
                 renderIncompatibilityInformation(mapping, indent + INDENTATION_UNIT, context, mode)
             }
-            if (index != unimplemented.lastIndex) {
+            if (index != unfulfilled.lastIndex) {
                 mode.newLine(this)
             }
         }
diff --git a/compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/output.txt b/compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/output.txt
index 837e5857de7..b687b2ebc2d 100644
--- a/compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/output.txt
+++ b/compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/jvm.kt:2:12: error: 'impl' constructor of 'Foo' has no corresponding 'header' declaration
+compiler/testData/multiplatform/classScopes/constructorIncorrectSignature/jvm.kt:2:12: error: actual constructor of 'Foo' has no corresponding expected declaration
 The following declaration is incompatible because parameter types are different:
     public constructor Foo(s: String)
 
diff --git a/compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/output.txt b/compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/output.txt
index f68a15be2ad..0a966348ea2 100644
--- a/compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/output.txt
+++ b/compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/output.txt
@@ -5,13 +5,13 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/jvm.kt:1:19: error: 'impl' enum class 'AB' has no corresponding 'header' declaration
+compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/jvm.kt:1:19: error: actual enum class 'AB' has no corresponding expected declaration
 The following declaration is incompatible because some entries from expected enum are missing in the actual enum:
     public final expect enum class AB : Enum<AB>
 
 actual enum class AB { A, C }
                   ^
-compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/jvm.kt:3:19: error: 'impl' enum class 'CD' has no corresponding 'header' declaration
+compiler/testData/multiplatform/classScopes/enumsWithDifferentEntries/jvm.kt:3:19: error: actual enum class 'CD' has no corresponding expected declaration
 The following declaration is incompatible because some entries from expected enum are missing in the actual enum:
     public final expect enum class CD : Enum<CD>
 
diff --git a/compiler/testData/multiplatform/classScopes/functionIncorrectSignature/output.txt b/compiler/testData/multiplatform/classScopes/functionIncorrectSignature/output.txt
index 5837e6517d3..7486e63e18d 100644
--- a/compiler/testData/multiplatform/classScopes/functionIncorrectSignature/output.txt
+++ b/compiler/testData/multiplatform/classScopes/functionIncorrectSignature/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/functionIncorrectSignature/jvm.kt:2:5: error: 'impl' function 'function' has no corresponding 'header' declaration
+compiler/testData/multiplatform/classScopes/functionIncorrectSignature/jvm.kt:2:5: error: actual function 'function' has no corresponding expected declaration
 The following declaration is incompatible because return type is different:
     public final expect fun function(b: ByteArray): Int
 
diff --git a/compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/output.txt b/compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/output.txt
index 323fd09762f..ef32266f705 100644
--- a/compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/output.txt
+++ b/compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/jvm.kt:5:14: error: 'impl' class 'Foo' has no implementation of 'header' class members:
+compiler/testData/multiplatform/classScopes/functionIncorrectSignatureFromSuperclass/jvm.kt:5:14: error: in class 'Foo' expected members have no actual ones:
 
     public final expect fun function(b: ByteArray): Int
 
diff --git a/compiler/testData/multiplatform/classScopes/missingConstructor/output.txt b/compiler/testData/multiplatform/classScopes/missingConstructor/output.txt
index 904cb0ac888..1481373ec1c 100644
--- a/compiler/testData/multiplatform/classScopes/missingConstructor/output.txt
+++ b/compiler/testData/multiplatform/classScopes/missingConstructor/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/missingConstructor/jvm.kt:1:14: error: 'impl' class 'Foo' has no implementation of 'header' class members:
+compiler/testData/multiplatform/classScopes/missingConstructor/jvm.kt:1:14: error: in class 'Foo' expected members have no actual ones:
 
     public constructor Foo(s: String)
 
diff --git a/compiler/testData/multiplatform/classScopes/missingFunction/output.txt b/compiler/testData/multiplatform/classScopes/missingFunction/output.txt
index 71d0bccab41..44f45cb3152 100644
--- a/compiler/testData/multiplatform/classScopes/missingFunction/output.txt
+++ b/compiler/testData/multiplatform/classScopes/missingFunction/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/classScopes/missingFunction/jvm.kt:1:14: error: 'impl' class 'Foo' has no implementation of 'header' class members:
+compiler/testData/multiplatform/classScopes/missingFunction/jvm.kt:1:14: error: in class 'Foo' expected members have no actual ones:
 
     public final expect fun function(s: String): Unit
 
diff --git a/compiler/testData/multiplatform/incompatibleCallables/output.txt b/compiler/testData/multiplatform/incompatibleCallables/output.txt
index 9192647b539..a126410af8b 100644
--- a/compiler/testData/multiplatform/incompatibleCallables/output.txt
+++ b/compiler/testData/multiplatform/incompatibleCallables/output.txt
@@ -8,115 +8,115 @@ expect fun f21(c: suspend Unit.() -> Unit)
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:1:1: error: 'impl' function 'f1' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:1:1: error: actual function 'f1' has no corresponding expected declaration
 The following declaration is incompatible because return type is different:
     public expect fun f1(): Unit
 
 actual fun f1(): String = ""
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:3:1: error: 'impl' function 'f2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:3:1: error: actual function 'f2' has no corresponding expected declaration
 The following declaration is incompatible because parameter names are different:
     public expect fun f2(name: String): Unit
 
 actual fun f2(otherName: String) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:5:1: error: 'impl' function 'f3' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:5:1: error: actual function 'f3' has no corresponding expected declaration
 The following declaration is incompatible because parameter types are different:
     public expect fun f3(name: String): Unit
 
 actual fun f3(name: Double) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:6:1: error: 'impl' function 'f3ext' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:6:1: error: actual function 'f3ext' has no corresponding expected declaration
 The following declaration is incompatible because parameter types are different:
     public expect fun String.f3ext(): Unit
 
 actual fun Double.f3ext() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:8:1: error: 'impl' function 'f4' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:8:1: error: actual function 'f4' has no corresponding expected declaration
 The following declaration is incompatible because parameter shapes are different (extension vs non-extension):
     public expect fun f4(name: String): Unit
 
 actual fun String.f4() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:10:1: error: 'impl' function 'f5' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:10:1: error: actual function 'f5' has no corresponding expected declaration
 The following declaration is incompatible because parameter shapes are different (extension vs non-extension):
     public expect fun String.f5(): Unit
 
 actual fun f5(name: String) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:12:1: error: 'impl' function 'f6' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:12:1: error: actual function 'f6' has no corresponding expected declaration
 The following declaration is incompatible because number of value parameters is different:
     public expect fun f6(p1: String, p2: Int): Unit
 
 actual fun f6(p2: Int) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:14:1: error: 'impl' function 'f7' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:14:1: error: actual function 'f7' has no corresponding expected declaration
 The following declaration is incompatible because number of type parameters is different:
     public expect fun <T> f7(): Unit
 
 actual fun <K, V> f7() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:16:1: error: 'impl' function 'f8' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:16:1: error: actual function 'f8' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     internal expect fun f8(): Unit
 
 public actual fun f8() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:17:1: error: 'impl' function 'f9' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:17:1: error: actual function 'f9' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     private expect fun f9(): Unit
 
 internal actual fun f9() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:18:1: error: 'impl' function 'f10' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:18:1: error: actual function 'f10' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     public expect fun f10(): Unit
 
 private actual fun f10() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:24:1: error: 'impl' function 'f14' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:24:1: error: actual function 'f14' has no corresponding expected declaration
 The following declaration is incompatible because some type parameter is reified in one declaration and non-reified in the other:
     public expect inline fun <X> f14(): Unit
 
 actual inline fun <reified X> f14() {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:27:1: error: 'impl' function 'f16' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:27:1: error: actual function 'f16' has no corresponding expected declaration
 The following declaration is incompatible because some parameters have default values:
     public expect fun f16(s: String): Unit
 
 actual fun f16(s: String = "") {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:29:1: error: 'impl' function 'f17' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:29:1: error: actual function 'f17' has no corresponding expected declaration
 The following declaration is incompatible because some value parameter is vararg in one declaration and non-vararg in the other:
     public expect fun f17(vararg s: String): Unit
 
 actual fun f17(s: Array<out String>) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:30:1: error: 'impl' function 'f18' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:30:1: error: actual function 'f18' has no corresponding expected declaration
 The following declaration is incompatible because some value parameter is vararg in one declaration and non-vararg in the other:
     public expect fun f18(s: Array<out String>): Unit
 
 actual fun f18(vararg s: String) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:31:1: error: 'impl' function 'f19' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:31:1: error: actual function 'f19' has no corresponding expected declaration
 The following declaration is incompatible because some value parameter is crossinline in one declaration and not crossinline in the other:
     public expect inline fun f19(s: () -> Unit): Unit
 
 actual inline fun f19(crossinline s: () -> Unit) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:32:1: error: 'impl' function 'f20' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:32:1: error: actual function 'f20' has no corresponding expected declaration
 The following declaration is incompatible because some value parameter is noinline in one declaration and not noinline in the other:
     public expect inline fun f20(s: () -> Unit): Unit
 
 actual inline fun f20(noinline s: () -> Unit) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:33:1: error: 'impl' function 'f21' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:33:1: error: actual function 'f21' has no corresponding expected declaration
 The following declaration is incompatible because parameter types are different:
     public expect fun f21(c: suspend Unit.() -> Unit): Unit
 
 actual fun f21(c: Unit.() -> Unit) {}
 ^
-compiler/testData/multiplatform/incompatibleCallables/jvm.kt:34:1: error: 'impl' function 'f22' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:34:1: error: actual function 'f22' has no corresponding expected declaration
 The following declaration is incompatible because parameter types are different:
     public expect fun f22(c: Unit.() -> Unit): Unit
 
diff --git a/compiler/testData/multiplatform/incompatibleClasses/output.txt b/compiler/testData/multiplatform/incompatibleClasses/output.txt
index a6414332c58..adb157b89fb 100644
--- a/compiler/testData/multiplatform/incompatibleClasses/output.txt
+++ b/compiler/testData/multiplatform/incompatibleClasses/output.txt
@@ -5,85 +5,85 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:1:18: error: 'impl' interface 'PClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:1:18: error: actual interface 'PClass' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public final expect class PClass
 
 actual interface PClass
                  ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:2:8: error: 'impl' object 'PInterface' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:2:8: error: actual object 'PInterface' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public expect interface PInterface
 
 actual object PInterface
        ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:3:19: error: 'impl' enum class 'PObject' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:3:19: error: actual enum class 'PObject' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public expect object PObject
 
 actual enum class PObject
                   ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:4:25: error: 'impl' annotation class 'PEnumClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:4:25: error: actual annotation class 'PEnumClass' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public final expect enum class PEnumClass : Enum<PEnumClass>
 
 actual annotation class PEnumClass
                         ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:5:14: error: 'impl' class 'PAnnotationClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:5:14: error: actual class 'PAnnotationClass' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public final expect annotation class PAnnotationClass : Annotation
 
 actual class PAnnotationClass
              ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:7:16: error: 'impl' object 'InternalObject' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:7:16: error: actual object 'InternalObject' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     internal expect object InternalObject
 
 private actual object InternalObject
                ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:8:17: error: 'impl' object 'PublicObject' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:8:17: error: actual object 'PublicObject' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     public expect object PublicObject
 
 internal actual object PublicObject
                 ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:9:15: error: 'impl' object 'PrivateObject' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:9:15: error: actual object 'PrivateObject' has no corresponding expected declaration
 The following declaration is incompatible because visibility is different:
     private expect object PrivateObject
 
 public actual object PrivateObject
               ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:11:20: error: 'impl' class 'OpenClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:11:20: error: actual class 'OpenClass' has no corresponding expected declaration
 The following declaration is incompatible because modality is different:
     public open expect class OpenClass
 
 final actual class OpenClass
                    ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:12:19: error: 'impl' class 'AbstractClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:12:19: error: actual class 'AbstractClass' has no corresponding expected declaration
 The following declaration is incompatible because modality is different:
     public abstract expect class AbstractClass
 
 open actual class AbstractClass
                   ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:13:23: error: 'impl' class 'FinalClass' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:13:23: error: actual class 'FinalClass' has no corresponding expected declaration
 The following declaration is incompatible because modality is different:
     public final expect class FinalClass
 
 abstract actual class FinalClass
                       ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:15:14: error: 'impl' class 'C1' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:15:14: error: actual class 'C1' has no corresponding expected declaration
 The following declaration is incompatible because number of type parameters is different:
     public final expect class C1<A>
 
 actual class C1<A, Extra>
              ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:16:14: error: 'impl' class 'C2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:16:14: error: actual class 'C2' has no corresponding expected declaration
 The following declaration is incompatible because declaration-site variances of type parameters are different:
     public final expect class C2<B>
 
 actual class C2<out B>
              ^
-compiler/testData/multiplatform/incompatibleClasses/jvm.kt:22:23: error: 'impl' class 'ExtendsNumber' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:22:23: error: actual class 'ExtendsNumber' has no corresponding expected declaration
 The following declaration is incompatible because some supertypes are missing in the actual declaration:
     public abstract expect class ExtendsNumber : Number
 
diff --git a/compiler/testData/multiplatform/incompatibleFunctions/output.txt b/compiler/testData/multiplatform/incompatibleFunctions/output.txt
index a1fb3e44cff..03f4d817165 100644
--- a/compiler/testData/multiplatform/incompatibleFunctions/output.txt
+++ b/compiler/testData/multiplatform/incompatibleFunctions/output.txt
@@ -5,31 +5,31 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:1:1: error: 'impl' function 'plus' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:1:1: error: actual function 'plus' has no corresponding expected declaration
 The following declaration is incompatible because some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec):
     public infix expect fun Int.plus(s: CharSequence): Int
 
 actual fun Int.plus(s: CharSequence): Int = 0
 ^
-compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:3:1: error: 'impl' function 'times' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:3:1: error: actual function 'times' has no corresponding expected declaration
 The following declaration is incompatible because some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec):
     public operator expect fun Double.times(x: CharArray): Unit
 
 actual fun Double.times(x: CharArray) {}
 ^
-compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:5:1: error: 'impl' function 'f1' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:5:1: error: actual function 'f1' has no corresponding expected declaration
 The following declaration is incompatible because some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec):
     public external expect fun f1(): Unit
 
 actual fun f1() {}
 ^
-compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:7:1: error: 'impl' function 'f2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:7:1: error: actual function 'f2' has no corresponding expected declaration
 The following declaration is incompatible because some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec):
     public expect inline fun f2(): Unit
 
 actual fun f2() {}
 ^
-compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:9:1: error: 'impl' function 'f3' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleFunctions/jvm.kt:9:1: error: actual function 'f3' has no corresponding expected declaration
 The following declaration is incompatible because some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec):
     public expect tailrec fun f3(): Unit
 
diff --git a/compiler/testData/multiplatform/incompatibleNestedClasses/output.txt b/compiler/testData/multiplatform/incompatibleNestedClasses/output.txt
index 96598e37169..9e85f86efed 100644
--- a/compiler/testData/multiplatform/incompatibleNestedClasses/output.txt
+++ b/compiler/testData/multiplatform/incompatibleNestedClasses/output.txt
@@ -5,49 +5,49 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:2:22: error: 'impl' interface 'N1' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:2:22: error: actual interface 'N1' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public final expect class N1
 
     actual interface N1
                      ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:3:12: error: 'impl' object 'N2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:3:12: error: actual object 'N2' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public expect interface N2
 
     actual object N2
            ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:4:18: error: 'impl' class 'N3' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:4:18: error: actual class 'N3' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public expect object N3
 
     actual class N3
                  ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:8:24: error: 'impl' class 'N2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:8:24: error: actual class 'N2' has no corresponding expected declaration
 The following declaration is incompatible because modifiers are different (companion, inner):
     public final expect class N2
 
     actual inner class N2
                        ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:9:18: error: 'impl' class 'I2' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:9:18: error: actual class 'I2' has no corresponding expected declaration
 The following declaration is incompatible because modifiers are different (companion, inner):
     public final expect inner class I2
 
     actual class I2
                  ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:13:22: error: 'impl' companion object 'Companion' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:13:22: error: actual companion object 'Companion' has no corresponding expected declaration
 The following declaration is incompatible because modifiers are different (companion, inner):
     public expect object Companion
 
     actual companion object {}
                      ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:14:12: error: 'impl' object 'Factory' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:14:12: error: actual object 'Factory' has no corresponding expected declaration
 The following declaration is incompatible because modifiers are different (companion, inner):
     public expect companion object Factory
 
     actual object Factory
            ^
-compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:18:12: error: 'impl' object 'Companion' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleNestedClasses/jvm.kt:18:12: error: actual object 'Companion' has no corresponding expected declaration
 The following declaration is incompatible because modifiers are different (companion, inner):
     public expect companion object
 
diff --git a/compiler/testData/multiplatform/incompatibleProperties/output.txt b/compiler/testData/multiplatform/incompatibleProperties/output.txt
index 33e10b497bf..092ceb55ed5 100644
--- a/compiler/testData/multiplatform/incompatibleProperties/output.txt
+++ b/compiler/testData/multiplatform/incompatibleProperties/output.txt
@@ -5,13 +5,13 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incompatibleProperties/jvm.kt:1:1: error: 'impl' property 'pval' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleProperties/jvm.kt:1:1: error: actual property 'pval' has no corresponding expected declaration
 The following declaration is incompatible because property kinds are different (val vs var):
     public expect val pval: String
 
 actual var pval: String = ""
 ^
-compiler/testData/multiplatform/incompatibleProperties/jvm.kt:2:1: error: 'impl' property 'pvar' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incompatibleProperties/jvm.kt:2:1: error: actual property 'pvar' has no corresponding expected declaration
 The following declaration is incompatible because property kinds are different (val vs var):
     public expect var pvar: String
 
diff --git a/compiler/testData/multiplatform/incorrectImplInClass/output.txt b/compiler/testData/multiplatform/incorrectImplInClass/output.txt
index 22bf6221699..787fcba93a8 100644
--- a/compiler/testData/multiplatform/incorrectImplInClass/output.txt
+++ b/compiler/testData/multiplatform/incorrectImplInClass/output.txt
@@ -5,15 +5,15 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:2:12: error: 'impl' constructor of 'Foo' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:2:12: error: actual constructor of 'Foo' has no corresponding expected declaration
 The following declaration is incompatible because number of value parameters is different:
     public constructor Foo()
 
     actual constructor(s: String) : this()
            ^
-compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:4:5: error: 'impl' function 'nonPlatformFun' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:4:5: error: actual function 'nonPlatformFun' has no corresponding expected declaration
     actual fun nonPlatformFun() {}
     ^
-compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:6:5: error: 'impl' property 'nonPlatformVal' has no corresponding 'header' declaration
+compiler/testData/multiplatform/incorrectImplInClass/jvm.kt:6:5: error: actual property 'nonPlatformVal' has no corresponding expected declaration
     actual val nonPlatformVal = ""
     ^
diff --git a/compiler/testData/multiplatform/missingOverload/output.txt b/compiler/testData/multiplatform/missingOverload/output.txt
index 3fa19d59f7f..5812172a44f 100644
--- a/compiler/testData/multiplatform/missingOverload/output.txt
+++ b/compiler/testData/multiplatform/missingOverload/output.txt
@@ -5,13 +5,13 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/missingOverload/common.kt:7:1: error: 'header' function 'g' has no implementation in module
+compiler/testData/multiplatform/missingOverload/common.kt:7:1: error: expected function 'g' has no actual in module
 The following declaration is incompatible because parameter types are different:
     public actual fun g(a: Any): Unit
 
 expect fun g(s: String)
 ^
-compiler/testData/multiplatform/missingOverload/jvm.kt:1:14: error: 'impl' class 'Foo' has no implementation of 'header' class members:
+compiler/testData/multiplatform/missingOverload/jvm.kt:1:14: error: in class 'Foo' expected members have no actual ones:
 
     public final expect fun f(a: Any): Unit
 
diff --git a/compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/output.txt b/compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/output.txt
index 9409841c961..14ad088cfc8 100644
--- a/compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/output.txt
+++ b/compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/output.txt
@@ -5,7 +5,7 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
-compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/jvm.kt:3:1: error: 'impl' class 'Writer' has no implementation of 'header' class members:
+compiler/testData/multiplatform/regressions/incompatibleClassScopesWithImplTypeAlias/jvm.kt:3:1: error: in class 'Writer' expected members have no actual ones:
 
     protected constructor Writer()
 
diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/IdeErrorMessages.java b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/IdeErrorMessages.java
index ff254dc0543..10933fb480d 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/IdeErrorMessages.java
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/IdeErrorMessages.java
@@ -175,13 +175,13 @@ public class IdeErrorMessages {
         MAP.put(EXPERIMENTAL_FEATURE_WARNING, "<html>{0}</html>", new LanguageFeatureMessageRenderer(LanguageFeatureMessageRenderer.Type.WARNING, true));
         MAP.put(EXPERIMENTAL_FEATURE_ERROR, "<html>{0}</html>", new LanguageFeatureMessageRenderer(LanguageFeatureMessageRenderer.Type.ERROR, true));
 
-        MAP.put(NO_ACTUAL_FOR_EXPECT, "<html>''header'' {0} has no implementation in module{1}{2}</html>", DECLARATION_NAME_WITH_KIND,
+        MAP.put(NO_ACTUAL_FOR_EXPECT, "<html>Expected {0} has no actual in module{1}{2}</html>", DECLARATION_NAME_WITH_KIND,
                 PLATFORM, new PlatformIncompatibilityDiagnosticRenderer(IdeMultiplatformDiagnosticRenderingMode.INSTANCE));
-        MAP.put(ACTUAL_WITHOUT_EXPECT, "<html>''impl'' {0} has no corresponding ''header'' declaration{1}</html>", DECLARATION_NAME_WITH_KIND,
+        MAP.put(ACTUAL_WITHOUT_EXPECT, "<html>Actual {0} has no corresponding expected declaration{1}</html>", DECLARATION_NAME_WITH_KIND,
                 new PlatformIncompatibilityDiagnosticRenderer(IdeMultiplatformDiagnosticRenderingMode.INSTANCE));
 
-        MAP.put(NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS, "<html>''impl'' class ''{0}'' has no implementation of ''header'' class members:{1}</html>",
-                NAME, new IncompatibleHeaderImplClassScopesRenderer(IdeMultiplatformDiagnosticRenderingMode.INSTANCE));
+        MAP.put(NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS, "<html>In class ''{0}'' expected members have no actual ones:{1}</html>",
+                NAME, new IncompatibleExpectedActualClassScopesRenderer(IdeMultiplatformDiagnosticRenderingMode.INSTANCE));
 
         MAP.setImmutable();
     }
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/basic/common/common.kt b/idea/testData/multiModuleHighlighting/multiplatform/basic/common/common.kt
index ea52485306c..49885064c03 100644
--- a/idea/testData/multiModuleHighlighting/multiplatform/basic/common/common.kt
+++ b/idea/testData/multiModuleHighlighting/multiplatform/basic/common/common.kt
@@ -1,3 +1,3 @@
-expect class <error descr="[NO_ACTUAL_FOR_EXPECT] 'header' class 'My' has no implementation in module jvm for JVM">My</error> {
+expect class <error descr="[NO_ACTUAL_FOR_EXPECT] Expected class 'My' has no actual in module jvm for JVM">My</error> {
 
 }
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt b/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
index c179ff49c2f..420dd83b9f8 100644
--- a/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
+++ b/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
@@ -1,8 +1,8 @@
-actual class <error descr="[ACTUAL_WITHOUT_EXPECT] 'impl' class 'Your' has no corresponding 'header' declaration">Your</error> {
+actual class <error descr="[ACTUAL_WITHOUT_EXPECT] Actual class 'Your' has no corresponding expected declaration">Your</error> {
 
 }
 
-expect class <error descr="[NO_ACTUAL_FOR_EXPECT] 'header' class 'His' has no implementation in module jvm for JVM">His</error> {
+expect class <error descr="[NO_ACTUAL_FOR_EXPECT] Expected class 'His' has no actual in module jvm for JVM">His</error> {
 
 }
 
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/headerWithoutImplForBoth/common/common.kt b/idea/testData/multiModuleHighlighting/multiplatform/headerWithoutImplForBoth/common/common.kt
index c2e87902564..2cd06749bb5 100644
--- a/idea/testData/multiModuleHighlighting/multiplatform/headerWithoutImplForBoth/common/common.kt
+++ b/idea/testData/multiModuleHighlighting/multiplatform/headerWithoutImplForBoth/common/common.kt
@@ -1,3 +1,3 @@
-expect class <error descr="[NO_ACTUAL_FOR_EXPECT] 'header' class 'My' has no implementation in module js for JS"><error descr="[NO_ACTUAL_FOR_EXPECT] 'header' class 'My' has no implementation in module jvm for JVM">My</error></error> {
+expect class <error descr="[NO_ACTUAL_FOR_EXPECT] Expected class 'My' has no actual in module js for JS"><error descr="[NO_ACTUAL_FOR_EXPECT] Expected class 'My' has no actual in module jvm for JVM">My</error></error> {
 
 }
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/suppressHeaderWithoutImpl/common/common.kt b/idea/testData/multiModuleHighlighting/multiplatform/suppressHeaderWithoutImpl/common/common.kt
index 0da57ae1110..e090b7100e0 100644
--- a/idea/testData/multiModuleHighlighting/multiplatform/suppressHeaderWithoutImpl/common/common.kt
+++ b/idea/testData/multiModuleHighlighting/multiplatform/suppressHeaderWithoutImpl/common/common.kt
@@ -4,4 +4,4 @@
 expect interface Event
 
 @Suppress("SOMETHING_WRONG")
-expect class <error descr="[NO_ACTUAL_FOR_EXPECT] 'header' class 'Wrong' has no implementation in module jvm for JVM">Wrong</error>
+expect class <error descr="[NO_ACTUAL_FOR_EXPECT] Expected class 'Wrong' has no actual in module jvm for JVM">Wrong</error>
diff --git a/idea/testData/quickfix/implement/doNotAddHeader.kt b/idea/testData/quickfix/implement/doNotAddHeader.kt
index 69c49b8799f..29abff7f091 100644
--- a/idea/testData/quickfix/implement/doNotAddHeader.kt
+++ b/idea/testData/quickfix/implement/doNotAddHeader.kt
@@ -1,6 +1,6 @@
 // "Implement members" "true"
 // WITH_RUNTIME
-// ERROR: 'header' interface 'InterfaceWithFuns' has no implementation in module light_idea_test_case for JVM
+// ERROR: Expected interface 'InterfaceWithFuns' has no actual in module light_idea_test_case for JVM
 expect interface InterfaceWithFuns {
     fun funInInterface()
 }
diff --git a/idea/testData/quickfix/implement/doNotAddHeader.kt.after b/idea/testData/quickfix/implement/doNotAddHeader.kt.after
index c4a8aa9e920..4d7f2bd8e9e 100644
--- a/idea/testData/quickfix/implement/doNotAddHeader.kt.after
+++ b/idea/testData/quickfix/implement/doNotAddHeader.kt.after
@@ -1,6 +1,6 @@
 // "Implement members" "true"
 // WITH_RUNTIME
-// ERROR: 'header' interface 'InterfaceWithFuns' has no implementation in module light_idea_test_case for JVM
+// ERROR: Expected interface 'InterfaceWithFuns' has no actual in module light_idea_test_case for JVM
 expect interface InterfaceWithFuns {
     fun funInInterface()
 }