diff --git a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
index 46e19df8222..3d78f389bac 100644
--- a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
+++ b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
@@ -35,10 +35,7 @@ import org.jetbrains.kotlin.fir.serialization.constant.EnumValue
 import org.jetbrains.kotlin.fir.serialization.constant.IntValue
 import org.jetbrains.kotlin.fir.serialization.constant.StringValue
 import org.jetbrains.kotlin.fir.serialization.constant.toConstantValue
-import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirClassifierSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
@@ -346,9 +343,9 @@ class FirElementSerializer private constructor(
             val nonSourceAnnotations = setter.nonSourceAnnotations(session)
             if (Flags.IS_NOT_DEFAULT.get(accessorFlags)) {
                 val setterLocal = local.createChildSerializer(setter)
-                for (valueParameterDescriptor in setter.valueParameters) {
+                for ((index, valueParameterDescriptor) in setter.valueParameters.withIndex()) {
                     val annotations = nonSourceAnnotations.filter { it.useSiteTarget == AnnotationUseSiteTarget.SETTER_PARAMETER }
-                    builder.setSetterValueParameter(setterLocal.valueParameterProto(valueParameterDescriptor, annotations))
+                    builder.setSetterValueParameter(setterLocal.valueParameterProto(valueParameterDescriptor, index, setter, annotations))
                 }
             }
         }
@@ -481,8 +478,8 @@ class FirElementSerializer private constructor(
             }
         }
 
-        for (valueParameter in function.valueParameters) {
-            builder.addValueParameter(local.valueParameterProto(valueParameter))
+        for ((index, valueParameter) in function.valueParameters.withIndex()) {
+            builder.addValueParameter(local.valueParameterProto(valueParameter, index, function))
         }
 
         contractSerializer.serializeContractOfFunctionIfAny(function, builder, this)
@@ -586,8 +583,8 @@ class FirElementSerializer private constructor(
             builder.flags = flags
         }
 
-        for (valueParameter in constructor.valueParameters) {
-            builder.addValueParameter(local.valueParameterProto(valueParameter))
+        for ((index, valueParameter) in constructor.valueParameters.withIndex()) {
+            builder.addValueParameter(local.valueParameterProto(valueParameter, index, constructor))
         }
 
         versionRequirementTable?.run {
@@ -609,11 +606,14 @@ class FirElementSerializer private constructor(
 
     private fun valueParameterProto(
         parameter: FirValueParameter,
+        index: Int,
+        function: FirFunction,
         additionalAnnotations: List<FirAnnotation> = emptyList()
     ): ProtoBuf.ValueParameter.Builder = whileAnalysing(session, parameter) {
         val builder = ProtoBuf.ValueParameter.newBuilder()
 
-        val declaresDefaultValue = parameter.defaultValue != null // TODO: || parameter.isActualParameterWithAnyExpectedDefault
+        val declaresDefaultValue = parameter.defaultValue != null ||
+                function.symbol.getSingleCompatibleExpectForActualOrNull().containsDefaultValue(index)
 
         val flags = Flags.getValueParameterFlags(
             additionalAnnotations.isNotEmpty() || parameter.nonSourceAnnotations(session).isNotEmpty(),
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt
index d7eab2d035b..cf1ae2ce687 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt
@@ -116,3 +116,7 @@ inline val FirBasedSymbol<*>.isJavaOrEnhancement: Boolean
     get() = origin.isJavaOrEnhancement ||
             (fir as? FirCallableDeclaration)?.importedFromObjectOrStaticData?.original?.isJavaOrEnhancement == true
 
+fun FirFunctionSymbol<*>?.containsDefaultValue(index: Int): Boolean {
+    if (this == null) return false
+    return this.fir.valueParameters[index].defaultValue != null
+}
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/FirDefaultParametersResolver.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/FirDefaultParametersResolver.kt
index edad2d0b80f..06ddef77326 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/FirDefaultParametersResolver.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/FirDefaultParametersResolver.kt
@@ -11,7 +11,6 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractImportingScope
-import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
 
 class FirDefaultParametersResolver : FirSessionComponent {
     fun declaresDefaultValue(
@@ -22,7 +21,7 @@ class FirDefaultParametersResolver : FirSessionComponent {
         originScope: FirScope?,
         index: Int,
     ): Boolean {
-        if (valueParameter.defaultValue != null || containsDefaultValue(function.symbol.getSingleCompatibleExpectForActualOrNull(), index)) {
+        if (valueParameter.defaultValue != null || function.symbol.getSingleCompatibleExpectForActualOrNull().containsDefaultValue(index)) {
             return true
         }
         if (function !is FirSimpleFunction) return false
@@ -44,10 +43,8 @@ class FirDefaultParametersResolver : FirSessionComponent {
         var result = false
 
         typeScope.processOverriddenFunctions(symbol) { overridden ->
-            if (containsDefaultValue(overridden, index) || containsDefaultValue(
-                    overridden.getSingleCompatibleExpectForActualOrNull(),
-                    index
-                )
+            if (overridden.containsDefaultValue(index) ||
+                overridden.getSingleCompatibleExpectForActualOrNull().containsDefaultValue(index)
             ) {
                 result = true
                 return@processOverriddenFunctions ProcessorAction.STOP
@@ -58,11 +55,6 @@ class FirDefaultParametersResolver : FirSessionComponent {
 
         return result
     }
-
-    private fun containsDefaultValue(functionSymbol: FirFunctionSymbol<*>?, index: Int): Boolean {
-        if (functionSymbol == null) return false
-        return functionSymbol.fir.valueParameters[index].defaultValue != null
-    }
 }
 
 internal val FirSession.defaultParameterResolver: FirDefaultParametersResolver by FirSession.sessionComponentAccessor()
diff --git a/compiler/testData/codegen/box/multiplatform/defaultArguments/functionFromOtherModule.kt b/compiler/testData/codegen/box/multiplatform/defaultArguments/functionFromOtherModule.kt
index 06c5f519679..a2649cd0f49 100644
--- a/compiler/testData/codegen/box/multiplatform/defaultArguments/functionFromOtherModule.kt
+++ b/compiler/testData/codegen/box/multiplatform/defaultArguments/functionFromOtherModule.kt
@@ -1,6 +1,6 @@
 // !LANGUAGE: +MultiPlatformProjects
 // IGNORE_BACKEND_K2: JVM_IR, JS_IR, NATIVE
-// FIR status: default argument mapping in MPP isn't designed yet
+// FIR status: expect/actual in the same module
 // WITH_STDLIB
 // MODULE: lib
 // FILE: common.kt
diff --git a/compiler/testData/codegen/box/multiplatform/defaultArguments/nestedEnumEntryValue.kt b/compiler/testData/codegen/box/multiplatform/defaultArguments/nestedEnumEntryValue.kt
index d5e674eaff6..06ac9590701 100644
--- a/compiler/testData/codegen/box/multiplatform/defaultArguments/nestedEnumEntryValue.kt
+++ b/compiler/testData/codegen/box/multiplatform/defaultArguments/nestedEnumEntryValue.kt
@@ -2,7 +2,7 @@
 // IGNORE_BACKEND: JS_IR, JS_IR_ES6, WASM
 //  JS IR & Wasm: https://youtrack.jetbrains.com/issue/KT-51225
 // IGNORE_BACKEND_K2: JVM_IR, NATIVE
-// FIR status: default argument mapping in MPP isn't designed yet
+// FIR status: expect/actual in the same module
 // !LANGUAGE: +MultiPlatformProjects
 // MODULE: lib
 // FILE: common.kt