diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/AnnotationCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/AnnotationCodegen.java
index 8664ddedc75..39569a249cb 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/AnnotationCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/AnnotationCodegen.java
@@ -349,7 +349,7 @@ public abstract class AnnotationCodegen {
     private String getAnnotationArgumentJvmName(@Nullable ClassDescriptor annotationClass, @NotNull Name parameterName) {
         if (annotationClass == null) return parameterName.asString();
 
-        Collection<PropertyDescriptor> variables =
+        Collection<? extends PropertyDescriptor> variables =
                 annotationClass.getUnsubstitutedMemberScope().getContributedVariables(parameterName, NoLookupLocation.FROM_BACKEND);
         if (variables.size() != 1) return parameterName.asString();
 
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java
index 75671846c2f..955949d4596 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java
@@ -467,7 +467,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             return;
         }
 
-        Collection<SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
+        Collection<? extends SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
                 Name.identifier("toArray"), NoLookupLocation.FROM_BACKEND
         );
         boolean hasGenericToArray = false;
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/kotlinSignature/SignaturesPropagationData.java b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/kotlinSignature/SignaturesPropagationData.java
index 1e5ee52ba74..e8a56cc3ac1 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/kotlinSignature/SignaturesPropagationData.java
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/kotlinSignature/SignaturesPropagationData.java
@@ -203,7 +203,7 @@ public class SignaturesPropagationData {
         Method autoSignature = null;
         boolean autoMethodContainsVararg = SignaturePropagationUtilKt.containsVarargs(autoMethodDescriptor);
         for (KotlinType supertype : containingClass.getTypeConstructor().getSupertypes()) {
-            Collection<SimpleFunctionDescriptor> superFunctionCandidates =
+            Collection<? extends SimpleFunctionDescriptor> superFunctionCandidates =
                     supertype.getMemberScope().getContributedFunctions(name, NoLookupLocation.WHEN_GET_SUPER_MEMBERS);
 
             if (!autoMethodContainsVararg && !SignaturePropagationUtilKt.containsAnyNotTrivialSignature(superFunctionCandidates)) continue;
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
index 9a05b291aff..7a29033e758 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
@@ -1187,8 +1187,9 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
         KotlinType refinedType = KotlinBuiltIns.isNothingOrNullableNothing(receiver.getType()) ?
                                  components.builtIns.getNullableAnyType() :
                                  receiver.getType();
-        Collection<SimpleFunctionDescriptor> equalsMembers = refinedType.getMemberScope().getContributedFunctions(
-                OperatorNameConventions.EQUALS, new KotlinLookupLocation(expression.getOperationReference()));
+        Collection<? extends SimpleFunctionDescriptor> equalsMembers = refinedType.getMemberScope().getContributedFunctions(
+                OperatorNameConventions.EQUALS, new KotlinLookupLocation(expression.getOperationReference())
+        );
 
         return CollectionsKt.filter(equalsMembers, descriptor -> {
             if (ErrorUtils.isError(descriptor)) return true;
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DataFlowAnalyzer.java b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DataFlowAnalyzer.java
index 619ea700236..a1438caaf98 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DataFlowAnalyzer.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DataFlowAnalyzer.java
@@ -99,8 +99,9 @@ public class DataFlowAnalyzer {
     }
 
     private boolean typeHasOverriddenEquals(@NotNull KotlinType type, @NotNull KtElement lookupElement) {
-        Collection<SimpleFunctionDescriptor> members = type.getMemberScope().getContributedFunctions(
-                OperatorNameConventions.EQUALS, new KotlinLookupLocation(lookupElement));
+        Collection<? extends SimpleFunctionDescriptor> members = type.getMemberScope().getContributedFunctions(
+                OperatorNameConventions.EQUALS, new KotlinLookupLocation(lookupElement)
+        );
         for (FunctionDescriptor member : members) {
             KotlinType returnType = member.getReturnType();
             if (returnType == null || !KotlinBuiltIns.isBoolean(returnType)) continue;
diff --git a/compiler/tests-common/tests/org/jetbrains/kotlin/resolve/annotation/AbstractAnnotationDescriptorResolveTest.java b/compiler/tests-common/tests/org/jetbrains/kotlin/resolve/annotation/AbstractAnnotationDescriptorResolveTest.java
index 778b8dc1f44..6c63f80fe26 100644
--- a/compiler/tests-common/tests/org/jetbrains/kotlin/resolve/annotation/AbstractAnnotationDescriptorResolveTest.java
+++ b/compiler/tests-common/tests/org/jetbrains/kotlin/resolve/annotation/AbstractAnnotationDescriptorResolveTest.java
@@ -169,7 +169,8 @@ public abstract class AbstractAnnotationDescriptorResolveTest extends KotlinTest
     protected static FunctionDescriptor getFunctionDescriptor(@NotNull PackageFragmentDescriptor packageView, @NotNull String name) {
         Name functionName = Name.identifier(name);
         MemberScope memberScope = packageView.getMemberScope();
-        Collection<SimpleFunctionDescriptor> functions = memberScope.getContributedFunctions(functionName, NoLookupLocation.FROM_TEST);
+        Collection<? extends SimpleFunctionDescriptor> functions =
+                memberScope.getContributedFunctions(functionName, NoLookupLocation.FROM_TEST);
         assert functions.size() == 1 : "Failed to find function " + functionName + " in class" + "." + packageView.getName();
         return functions.iterator().next();
     }
@@ -178,7 +179,8 @@ public abstract class AbstractAnnotationDescriptorResolveTest extends KotlinTest
     private static FunctionDescriptor getFunctionDescriptor(@NotNull ClassDescriptor classDescriptor, @NotNull String name) {
         Name functionName = Name.identifier(name);
         MemberScope memberScope = classDescriptor.getMemberScope(Collections.emptyList());
-        Collection<SimpleFunctionDescriptor> functions = memberScope.getContributedFunctions(functionName, NoLookupLocation.FROM_TEST);
+        Collection<? extends SimpleFunctionDescriptor> functions =
+                memberScope.getContributedFunctions(functionName, NoLookupLocation.FROM_TEST);
         assert functions.size() == 1 : "Failed to find function " + functionName + " in class" + "." + classDescriptor.getName();
         return functions.iterator().next();
     }
@@ -187,12 +189,13 @@ public abstract class AbstractAnnotationDescriptorResolveTest extends KotlinTest
     protected static PropertyDescriptor getPropertyDescriptor(@NotNull PackageFragmentDescriptor packageView, @NotNull String name, boolean failOnMissing) {
         Name propertyName = Name.identifier(name);
         MemberScope memberScope = packageView.getMemberScope();
-        Collection<PropertyDescriptor> properties = memberScope.getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
+        Collection<? extends PropertyDescriptor> properties = memberScope.getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
         if (properties.isEmpty()) {
             for (DeclarationDescriptor descriptor : DescriptorUtils.getAllDescriptors(memberScope)) {
                 if (descriptor instanceof ClassDescriptor) {
-                    Collection<PropertyDescriptor> classProperties = ((ClassDescriptor) descriptor).getMemberScope(Collections.emptyList())
-                            .getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
+                    Collection<? extends PropertyDescriptor> classProperties =
+                            ((ClassDescriptor) descriptor).getMemberScope(Collections.emptyList())
+                                    .getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
                     if (!classProperties.isEmpty()) {
                         properties = classProperties;
                         break;
@@ -213,7 +216,7 @@ public abstract class AbstractAnnotationDescriptorResolveTest extends KotlinTest
     private static PropertyDescriptor getPropertyDescriptor(@NotNull ClassDescriptor classDescriptor, @NotNull String name) {
         Name propertyName = Name.identifier(name);
         MemberScope memberScope = classDescriptor.getMemberScope(Collections.emptyList());
-        Collection<PropertyDescriptor> properties = memberScope.getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
+        Collection<? extends PropertyDescriptor> properties = memberScope.getContributedVariables(propertyName, NoLookupLocation.FROM_TEST);
         assert properties.size() == 1 : "Failed to find property " + propertyName + " in class " + classDescriptor.getName();
         return properties.iterator().next();
     }
diff --git a/compiler/tests/org/jetbrains/kotlin/types/BoundsSubstitutorTest.java b/compiler/tests/org/jetbrains/kotlin/types/BoundsSubstitutorTest.java
index 23a16fff12a..91789ef7b34 100644
--- a/compiler/tests/org/jetbrains/kotlin/types/BoundsSubstitutorTest.java
+++ b/compiler/tests/org/jetbrains/kotlin/types/BoundsSubstitutorTest.java
@@ -72,7 +72,7 @@ public class BoundsSubstitutorTest extends KotlinTestWithEnvironment {
     private void doTest(String text, String expected) {
         KtFile ktFile = KtPsiFactoryKt.KtPsiFactory(getProject()).createFile("fun.kt", text);
         ModuleDescriptor module = JvmResolveUtil.analyze(ktFile, getEnvironment()).getModuleDescriptor();
-        Collection<SimpleFunctionDescriptor> functions =
+        Collection<? extends SimpleFunctionDescriptor> functions =
                 module.getPackage(FqName.ROOT).getMemberScope().getContributedFunctions(Name.identifier("f"), NoLookupLocation.FROM_TEST);
         FunctionDescriptor substituted = BoundsSubstitutor.substituteBounds(CollectionsKt.single(functions));
         String actual = DescriptorRenderer.COMPACT.render(substituted);
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 655a800ac00..195eac21cb1 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/EnumEntrySyntheticClassDescriptor.java
@@ -182,21 +182,21 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
     }
 
     private class EnumEntryScope extends MemberScopeImpl {
-        private final MemoizedFunctionToNotNull<Name, Collection<SimpleFunctionDescriptor>> functions;
-        private final MemoizedFunctionToNotNull<Name, Collection<PropertyDescriptor>> properties;
+        private final MemoizedFunctionToNotNull<Name, Collection<? extends SimpleFunctionDescriptor>> functions;
+        private final MemoizedFunctionToNotNull<Name, Collection<? extends PropertyDescriptor>> properties;
         private final NotNullLazyValue<Collection<DeclarationDescriptor>> allDescriptors;
 
         public EnumEntryScope(@NotNull StorageManager storageManager) {
-            this.functions = storageManager.createMemoizedFunction(new Function1<Name, Collection<SimpleFunctionDescriptor>>() {
+            this.functions = storageManager.createMemoizedFunction(new Function1<Name, Collection<? extends SimpleFunctionDescriptor>>() {
                 @Override
-                public Collection<SimpleFunctionDescriptor> invoke(Name name) {
+                public Collection<? extends SimpleFunctionDescriptor> invoke(Name name) {
                     return computeFunctions(name);
                 }
             });
 
-            this.properties = storageManager.createMemoizedFunction(new Function1<Name, Collection<PropertyDescriptor>>() {
+            this.properties = storageManager.createMemoizedFunction(new Function1<Name, Collection<? extends PropertyDescriptor>>() {
                 @Override
-                public Collection<PropertyDescriptor> invoke(Name name) {
+                public Collection<? extends PropertyDescriptor> invoke(Name name) {
                     return computeProperties(name);
                 }
             });
@@ -210,32 +210,23 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
 
         @NotNull
         @Override
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        public Collection getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
+        public Collection<? extends PropertyDescriptor> getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
             return properties.invoke(name);
         }
 
         @NotNull
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        private Collection<PropertyDescriptor> computeProperties(@NotNull Name name) {
-            return resolveFakeOverrides(name, (Collection) getSupertypeScope().getContributedVariables(name, NoLookupLocation.FOR_NON_TRACKED_SCOPE));
+        private Collection<? extends PropertyDescriptor> computeProperties(@NotNull Name name) {
+            return resolveFakeOverrides(name, getSupertypeScope().getContributedVariables(name, NoLookupLocation.FOR_NON_TRACKED_SCOPE));
         }
 
         @NotNull
         @Override
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        public Collection getContributedFunctions(@NotNull Name name, @NotNull LookupLocation location) {
+        public Collection<? extends SimpleFunctionDescriptor> getContributedFunctions(@NotNull Name name, @NotNull LookupLocation location) {
             return functions.invoke(name);
         }
 
         @NotNull
-        private Collection<SimpleFunctionDescriptor> computeFunctions(@NotNull Name name) {
+        private Collection<? extends SimpleFunctionDescriptor> computeFunctions(@NotNull Name name) {
             return resolveFakeOverrides(name, getSupertypeScope().getContributedFunctions(name, NoLookupLocation.FOR_NON_TRACKED_SCOPE));
         }
 
@@ -247,9 +238,9 @@ public class EnumEntrySyntheticClassDescriptor extends ClassDescriptorBase {
         }
 
         @NotNull
-        private <D extends CallableMemberDescriptor> Collection<D> resolveFakeOverrides(
+        private <D extends CallableMemberDescriptor> Collection<? extends D> resolveFakeOverrides(
                 @NotNull Name name,
-                @NotNull Collection<D> fromSupertypes
+                @NotNull Collection<? extends D> fromSupertypes
         ) {
             final Set<D> result = new LinkedHashSet<D>();
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.java b/core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.java
index 0dcbb446779..837e4816565 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.java
@@ -587,8 +587,7 @@ public class DescriptorUtils {
 
     @Nullable
     public static FunctionDescriptor getFunctionByNameOrNull(@NotNull MemberScope scope, @NotNull Name name) {
-        Collection<SimpleFunctionDescriptor> functions = scope.getContributedFunctions(name, NoLookupLocation.FROM_BACKEND);
-        for (SimpleFunctionDescriptor d : functions) {
+        for (SimpleFunctionDescriptor d : scope.getContributedFunctions(name, NoLookupLocation.FROM_BACKEND)) {
             if (name.equals(d.getOriginal().getName())) {
                 return d;
             }
@@ -599,8 +598,7 @@ public class DescriptorUtils {
 
     @NotNull
     public static PropertyDescriptor getPropertyByName(@NotNull MemberScope scope, @NotNull Name name) {
-        Collection<PropertyDescriptor> properties = scope.getContributedVariables(name, NoLookupLocation.FROM_BACKEND);
-        for (PropertyDescriptor d : properties) {
+        for (PropertyDescriptor d : scope.getContributedVariables(name, NoLookupLocation.FROM_BACKEND)) {
             if (name.equals(d.getOriginal().getName())) {
                 return d;
             }
diff --git a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScope.kt b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScope.kt
index 997a35a59e9..d5c9a9d1253 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScope.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScope.kt
@@ -25,8 +25,9 @@ import java.lang.reflect.Modifier
 
 interface MemberScope : ResolutionScope {
 
-    override fun getContributedVariables(name: Name, location: LookupLocation): Collection<PropertyDescriptor>
-    override fun getContributedFunctions(name: Name, location: LookupLocation): Collection<SimpleFunctionDescriptor>
+    override fun getContributedVariables(name: Name, location: LookupLocation): Collection<@JvmWildcard PropertyDescriptor>
+
+    override fun getContributedFunctions(name: Name, location: LookupLocation): Collection<@JvmWildcard SimpleFunctionDescriptor>
 
     /**
      * These methods may return a superset of an actual names' set
diff --git a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScopeImpl.kt b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScopeImpl.kt
index 773936d5a4d..d4708d062c5 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScopeImpl.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/MemberScopeImpl.kt
@@ -25,9 +25,11 @@ import org.jetbrains.kotlin.utils.alwaysTrue
 abstract class MemberScopeImpl : MemberScope {
     override fun getContributedClassifier(name: Name, location: LookupLocation): ClassifierDescriptor? = null
 
-    override fun getContributedVariables(name: Name, location: LookupLocation): Collection<PropertyDescriptor> = emptyList()
+    override fun getContributedVariables(name: Name, location: LookupLocation): Collection<@JvmWildcard PropertyDescriptor> =
+        emptyList()
 
-    override fun getContributedFunctions(name: Name, location: LookupLocation): Collection<SimpleFunctionDescriptor> = emptyList()
+    override fun getContributedFunctions(name: Name, location: LookupLocation): Collection<@JvmWildcard SimpleFunctionDescriptor> =
+        emptyList()
 
     override fun getContributedDescriptors(kindFilter: DescriptorKindFilter,
                                            nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> = emptyList()
diff --git a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/ResolutionScope.kt b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/ResolutionScope.kt
index 664754fc8b1..3f1299bac42 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/ResolutionScope.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/ResolutionScope.kt
@@ -39,9 +39,9 @@ interface ResolutionScope {
     fun getContributedClassifierIncludeDeprecated(name: Name, location: LookupLocation): DescriptorWithDeprecation<ClassifierDescriptor>? =
         getContributedClassifier(name, location)?.let { DescriptorWithDeprecation.createNonDeprecated(it) }
 
-    fun getContributedVariables(name: Name, location: LookupLocation): Collection<VariableDescriptor>
+    fun getContributedVariables(name: Name, location: LookupLocation): Collection<@JvmWildcard VariableDescriptor>
 
-    fun getContributedFunctions(name: Name, location: LookupLocation): Collection<FunctionDescriptor>
+    fun getContributedFunctions(name: Name, location: LookupLocation): Collection<@JvmWildcard FunctionDescriptor>
 
     /**
      * All visible descriptors from current scope possibly filtered by the given name and kind filters
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java b/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
index 90f3fd1ca32..2ac355fe2a9 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
@@ -198,19 +198,13 @@ public class ErrorUtils {
 
         @NotNull
         @Override
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        public Set getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
+        public Set<? extends PropertyDescriptor> getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
             return ERROR_PROPERTY_GROUP;
         }
 
         @NotNull
         @Override
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        public Set getContributedFunctions(@NotNull Name name, @NotNull LookupLocation location) {
+        public Set<? extends SimpleFunctionDescriptor> getContributedFunctions(@NotNull Name name, @NotNull LookupLocation location) {
             return Collections.singleton(createErrorFunction(this));
         }
 
@@ -284,17 +278,15 @@ public class ErrorUtils {
 
         @NotNull
         @Override
-        @SuppressWarnings({"unchecked"}) // KT-9898 Impossible implement kotlin interface from java
-        public Collection getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
+        public Collection<? extends PropertyDescriptor> getContributedVariables(@NotNull Name name, @NotNull LookupLocation location) {
             throw new IllegalStateException(debugMessage+", required name: " + name);
         }
 
         @NotNull
         @Override
-        // TODO: Convert to Kotlin or add @JvmWildcard to MemberScope declarations
-        // method is covariantly overridden in Kotlin, but collections in Java are invariant
-        @SuppressWarnings({"unchecked"})
-        public Collection getContributedFunctions(@NotNull Name name, @NotNull LookupLocation location) {
+        public Collection<? extends SimpleFunctionDescriptor> getContributedFunctions(
+                @NotNull Name name, @NotNull LookupLocation location
+        ) {
             throw new IllegalStateException(debugMessage+", required name: " + name);
         }
 
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
index cd9306d098e..715002f3fc7 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
@@ -216,8 +216,9 @@ public final class Namer {
     // TODO: get rid of this function
     @NotNull
     private static String getStableMangledNameForDescriptor(@NotNull ClassDescriptor descriptor, @NotNull String functionName) {
-        Collection<SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
-                Name.identifier(functionName), NoLookupLocation.FROM_BACKEND);
+        Collection<? extends SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
+                Name.identifier(functionName), NoLookupLocation.FROM_BACKEND
+        );
         assert functions.size() == 1 : "Can't select a single function: " + functionName + " in " + descriptor;
         SuggestedName suggested = new NameSuggestion().suggest(functions.iterator().next());
         assert suggested != null : "Suggested name for class members is always non-null: " + functions.iterator().next();
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallExpressionTranslator.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallExpressionTranslator.java
index cd4e7cd5780..497714af80e 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallExpressionTranslator.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallExpressionTranslator.java
@@ -152,7 +152,7 @@ public final class CallExpressionTranslator extends AbstractCallExpressionTransl
     @Nullable
     private static VariableDescriptor getVariableByName(@NotNull LexicalScope scope, @NotNull Name name) {
         while (true) {
-            Collection<VariableDescriptor> variables = scope.getContributedVariables(name, NoLookupLocation.FROM_BACKEND);
+            Collection<? extends VariableDescriptor> variables = scope.getContributedVariables(name, NoLookupLocation.FROM_BACKEND);
             if (!variables.isEmpty()) {
                 return variables.size() == 1 ? variables.iterator().next() : null;
             }