diff --git a/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt b/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt
index 3d391c17af2..d70875ec983 100644
--- a/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt
+++ b/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt
@@ -20,11 +20,14 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.backend.common.bridges.findInterfaceImplementation
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.diagnostics.DiagnosticSink
+import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.hasExpectModifier
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsExpression
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
@@ -175,4 +178,29 @@ object CodegenUtil {
         }
         return compatibleExpectedFunctions.firstOrNull() as FunctionDescriptor?
     }
+
+    @JvmStatic
+    fun getFunctionParametersForDefaultValueGeneration(
+        descriptor: FunctionDescriptor,
+        trace: DiagnosticSink?
+    ): List<ValueParameterDescriptor> {
+        if (descriptor.isActual) {
+            val expected = CodegenUtil.findExpectedFunctionForActual(descriptor)
+            if (expected != null && expected.valueParameters.any(ValueParameterDescriptor::declaresDefaultValue)) {
+                val element = DescriptorToSourceUtils.descriptorToDeclaration(expected)
+                if (element == null) {
+                    if (trace != null) {
+                        val actualDeclaration = DescriptorToSourceUtils.descriptorToDeclaration(descriptor)
+                                ?: error("Not a source declaration: $descriptor")
+                        trace.report(Errors.EXPECTED_FUNCTION_SOURCE_WITH_DEFAULT_ARGUMENTS_NOT_FOUND.on(actualDeclaration))
+                    }
+                    return descriptor.valueParameters
+                }
+
+                return expected.valueParameters
+            }
+        }
+
+        return descriptor.valueParameters
+    }
 }
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java
index ee4c5252400..c260c817255 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java
@@ -74,7 +74,6 @@ import static org.jetbrains.kotlin.descriptors.CallableMemberDescriptor.Kind.DEC
 import static org.jetbrains.kotlin.descriptors.ModalityKt.isOverridable;
 import static org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget.*;
 import static org.jetbrains.kotlin.descriptors.annotations.AnnotationUtilKt.isEffectivelyInlineOnly;
-import static org.jetbrains.kotlin.diagnostics.Errors.EXPECTED_FUNCTION_SOURCE_WITH_DEFAULT_ARGUMENTS_NOT_FOUND;
 import static org.jetbrains.kotlin.resolve.DescriptorToSourceUtils.getSourceFromDescriptor;
 import static org.jetbrains.kotlin.resolve.DescriptorUtils.*;
 import static org.jetbrains.kotlin.resolve.jvm.AsmTypes.OBJECT_TYPE;
@@ -1110,16 +1109,9 @@ public class FunctionCodegen {
         GenerationState state = parentCodegen.state;
         JvmMethodSignature signature = state.getTypeMapper().mapSignatureWithGeneric(functionDescriptor, methodContext.getContextKind());
 
-        List<ValueParameterDescriptor> originalParameters = functionDescriptor.getValueParameters();
-        List<ValueParameterDescriptor> valueParameters;
-        if (functionDescriptor.isActual() && CollectionsKt.none(originalParameters, ValueParameterDescriptor::declaresDefaultValue)) {
-            FunctionDescriptor expected = CodegenUtil.findExpectedFunctionForActual(functionDescriptor);
-            assert expected != null : "Expected function should have been found earlier for " + functionDescriptor;
-            valueParameters = expected.getValueParameters();
-        }
-        else {
-            valueParameters = originalParameters;
-        }
+        // 'null' because the "could not find expected declaration" error has been already reported in isDefaultNeeded earlier
+        List<ValueParameterDescriptor> valueParameters =
+                CodegenUtil.getFunctionParametersForDefaultValueGeneration(functionDescriptor, null);
 
         boolean isStatic = isStaticMethod(methodContext.getContextKind(), functionDescriptor);
         FrameMap frameMap = createFrameMap(state, signature, functionDescriptor.getExtensionReceiverParameter(), valueParameters, isStatic);
@@ -1260,22 +1252,9 @@ public class FunctionCodegen {
     }
 
     private boolean isDefaultNeeded(@NotNull FunctionDescriptor descriptor, @Nullable KtNamedFunction function) {
-        if (descriptor.isActual()) {
-            FunctionDescriptor expected = CodegenUtil.findExpectedFunctionForActual(descriptor);
-            if (expected != null && CollectionsKt.any(expected.getValueParameters(), ValueParameterDescriptor::declaresDefaultValue)) {
-                PsiElement element = DescriptorToSourceUtils.descriptorToDeclaration(expected);
-                if (element == null) {
-                    if (function != null) {
-                        state.getDiagnostics().report(EXPECTED_FUNCTION_SOURCE_WITH_DEFAULT_ARGUMENTS_NOT_FOUND.on(function));
-                    }
-                    return false;
-                }
-
-                return true;
-            }
-        }
-
-        return CollectionsKt.any(descriptor.getValueParameters(), ValueParameterDescriptor::declaresDefaultValue);
+        List<ValueParameterDescriptor> parameters =
+                CodegenUtil.getFunctionParametersForDefaultValueGeneration(descriptor, state.getDiagnostics());
+        return CollectionsKt.any(parameters, ValueParameterDescriptor::declaresDefaultValue);
     }
 
     private void generateBridge(
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java
index 09859db8069..727ee69f9a1 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java
@@ -17,7 +17,6 @@
 package org.jetbrains.kotlin.js.translate.utils;
 
 import com.intellij.psi.PsiElement;
-import kotlin.collections.CollectionsKt;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.backend.common.CodegenUtil;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
@@ -25,7 +24,6 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor;
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor;
-import org.jetbrains.kotlin.diagnostics.Errors;
 import org.jetbrains.kotlin.js.backend.ast.*;
 import org.jetbrains.kotlin.js.backend.ast.metadata.MetadataProperties;
 import org.jetbrains.kotlin.js.naming.NameSuggestion;
@@ -38,7 +36,6 @@ import org.jetbrains.kotlin.js.translate.reference.ReferenceTranslator;
 import org.jetbrains.kotlin.psi.KtBlockExpression;
 import org.jetbrains.kotlin.psi.KtDeclarationWithBody;
 import org.jetbrains.kotlin.psi.KtExpression;
-import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils;
 import org.jetbrains.kotlin.resolve.source.KotlinSourceElementKt;
 import org.jetbrains.kotlin.types.KotlinType;
 
@@ -83,22 +80,8 @@ public final class FunctionBodyTranslator extends AbstractTranslator {
             @NotNull TranslationContext context
     ) {
         List<ValueParameterDescriptor> valueParameters = descriptor.getValueParameters();
-        List<ValueParameterDescriptor> valueParametersForDefaultValue;
-        if (descriptor.isActual() && CollectionsKt.none(valueParameters, ValueParameterDescriptor::declaresDefaultValue)) {
-            FunctionDescriptor expected = CodegenUtil.findExpectedFunctionForActual(descriptor);
-            if (expected != null) {
-                valueParametersForDefaultValue = expected.getValueParameters();
-            }
-            else {
-                PsiElement element = DescriptorToSourceUtils.descriptorToDeclaration(descriptor);
-                assert element != null : "No element found for descriptor: " + descriptor;
-                context.bindingTrace().report(Errors.EXPECTED_FUNCTION_SOURCE_WITH_DEFAULT_ARGUMENTS_NOT_FOUND.on(element));
-                valueParametersForDefaultValue = valueParameters;
-            }
-        }
-        else {
-            valueParametersForDefaultValue = valueParameters;
-        }
+        List<ValueParameterDescriptor> valueParametersForDefaultValue =
+                CodegenUtil.getFunctionParametersForDefaultValueGeneration(descriptor, context.bindingTrace());
 
         List<JsStatement> result = new ArrayList<>(valueParameters.size());
         for (int i = 0; i < valueParameters.size(); i++) {