diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
index afb792d4a19..505d7fdbcaa 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
@@ -68,6 +68,7 @@ class JvmBackendContext(
 
     internal val multifileFacadesToAdd = mutableMapOf<JvmClassName, MutableList<IrClass>>()
     internal val multifileFacadeForPart = mutableMapOf<IrClass, JvmClassName>()
+    internal val multifileFacadeMemberToPartMember = mutableMapOf<IrFunctionSymbol, IrFunctionSymbol>()
 
     override var inVerbosePhase: Boolean = false
 
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/IrSourceCompilerForInline.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/IrSourceCompilerForInline.kt
index 5615a45a0bb..ce9c4d8743b 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/IrSourceCompilerForInline.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/IrSourceCompilerForInline.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.backend.jvm.codegen
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import org.jetbrains.kotlin.backend.common.ir.ir2string
+import org.jetbrains.kotlin.backend.jvm.lower.MultifileFacadeFileEntry
 import org.jetbrains.kotlin.codegen.BaseExpressionCodegen
 import org.jetbrains.kotlin.codegen.ClassBuilder
 import org.jetbrains.kotlin.codegen.OwnerKind
@@ -23,6 +24,7 @@ import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrMemberAccessExpression
 import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodGenericSignature
@@ -102,9 +104,10 @@ class IrSourceCompilerForInline(
 
     private fun getFunctionToInline(call: IrCall, jvmSignature: JvmMethodSignature, callDefault: Boolean): IrFunction {
         val callee = call.symbol.owner
+        val parent = callee.parentAsClass
         if (callDefault) {
             /*TODO: get rid of hack*/
-            return callee.parentAsClass.declarations.filterIsInstance<IrFunction>().single {
+            return parent.declarations.filterIsInstance<IrFunction>().single {
                 it.descriptor.name.asString() == jvmSignature.asmMethod.name + JvmAbi.DEFAULT_PARAMS_IMPL_SUFFIX &&
                         codegen.context.methodSignatureMapper.mapSignatureSkipGeneric(callee).asmMethod.descriptor.startsWith(
                             jvmSignature.asmMethod.descriptor.substringBeforeLast(')')
@@ -112,6 +115,11 @@ class IrSourceCompilerForInline(
             }
         }
 
+        if (parent.fileParent.fileEntry is MultifileFacadeFileEntry) {
+            return (codegen.context.multifileFacadeMemberToPartMember[callee.symbol]
+                ?: error("Function from a multi-file facade without the link to the function in the part: ${callee.render()}")).owner
+        }
+
         return callee
     }
 
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
index 9ea586fca17..1609aeb8332 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
@@ -32,10 +32,14 @@ import org.jetbrains.kotlin.ir.builders.irReturn
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFieldImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
+import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrGetField
+import org.jetbrains.kotlin.ir.expressions.copyTypeArgumentsFrom
+import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetFieldImpl
 import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
+import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
 import org.jetbrains.kotlin.ir.util.dump
 import org.jetbrains.kotlin.ir.util.transformFlat
@@ -55,9 +59,17 @@ internal val generateMultifileFacadesPhase = namedIrModulePhase(
             input: IrModuleFragment
         ): IrModuleFragment {
             val movedFields = mutableMapOf<IrFieldSymbol, IrFieldSymbol>()
-            input.files.addAll(generateMultifileFacades(input.descriptor, context, movedFields))
+            val functionDelegates = mutableMapOf<IrFunctionSymbol, IrFunctionSymbol>()
+
+            input.files.addAll(generateMultifileFacades(input.descriptor, context, movedFields, functionDelegates))
+
             UpdateFieldCallSites(movedFields).lower(input)
+            UpdateFunctionCallSites(functionDelegates).lower(input)
+
             context.multifileFacadesToAdd.clear()
+
+            functionDelegates.entries.associateTo(context.multifileFacadeMemberToPartMember) { (member, newMember) -> newMember to member }
+
             return input
         }
     }
@@ -86,7 +98,8 @@ internal class MultifileFacadeFileEntry(
 private fun generateMultifileFacades(
     module: ModuleDescriptor,
     context: JvmBackendContext,
-    movedFields: MutableMap<IrFieldSymbol, IrFieldSymbol>
+    movedFields: MutableMap<IrFieldSymbol, IrFieldSymbol>,
+    functionDelegates: MutableMap<IrFunctionSymbol, IrFunctionSymbol>
 ): List<IrFile> =
     context.multifileFacadesToAdd.map { (jvmClassName, partClasses) ->
         val fileEntry = MultifileFacadeFileEntry(jvmClassName, partClasses.map(IrClass::fileParent))
@@ -106,7 +119,12 @@ private fun generateMultifileFacades(
             moveFieldsOfConstProperties(partClass, facadeClass, movedFields)
 
             for (member in partClass.declarations) {
-                member.createMultifileDelegateIfNeeded(context, facadeClass)
+                if (member is IrFunction) {
+                    val newMember = member.createMultifileDelegateIfNeeded(context, facadeClass)
+                    if (newMember != null) {
+                        functionDelegates[member.symbol] = newMember.symbol
+                    }
+                }
             }
         }
 
@@ -135,12 +153,11 @@ private fun IrField.shouldMoveToFacade(): Boolean {
     return property != null && property.isConst && !Visibilities.isPrivate(visibility)
 }
 
-private fun IrDeclaration.createMultifileDelegateIfNeeded(context: JvmBackendContext, facadeClass: IrClass) {
-    if (this !is IrFunction ||
-        Visibilities.isPrivate(visibility) ||
+private fun IrFunction.createMultifileDelegateIfNeeded(context: JvmBackendContext, facadeClass: IrClass): IrFunction? {
+    if (Visibilities.isPrivate(visibility) ||
         name == InitializersLowering.clinitName ||
         origin == JvmLoweredDeclarationOrigin.SYNTHETIC_ACCESSOR
-    ) return
+    ) return null
 
     // TODO: perform copy of the signature only, without body
     val function = deepCopyWithSymbols(facadeClass)
@@ -158,6 +175,8 @@ private fun IrDeclaration.createMultifileDelegateIfNeeded(context: JvmBackendCon
     function.origin = JvmLoweredDeclarationOrigin.MULTIFILE_BRIDGE
 
     facadeClass.declarations.add(function)
+
+    return function
 }
 
 // This deep copy is needed while we still use KotlinTypeMapper to map signatures in method calls. Without it, KotlinTypeMapper takes
@@ -190,3 +209,24 @@ private class UpdateFieldCallSites(
         }
     }
 }
+
+private class UpdateFunctionCallSites(
+    private val functionDelegates: MutableMap<IrFunctionSymbol, IrFunctionSymbol>
+) : FileLoweringPass, IrElementTransformerVoid() {
+    override fun lower(irFile: IrFile) {
+        irFile.transformChildrenVoid(this)
+    }
+
+    override fun visitCall(expression: IrCall): IrExpression {
+        val newFunction = functionDelegates[expression.symbol] ?: return super.visitCall(expression)
+        return expression.run {
+            IrCallImpl(startOffset, endOffset, type, newFunction).apply {
+                copyTypeArgumentsFrom(expression)
+                extensionReceiver = expression.extensionReceiver?.transform(this@UpdateFunctionCallSites, null)
+                for (i in 0 until valueArgumentsCount) {
+                    putValueArgument(i, expression.getValueArgument(i)?.transform(this@UpdateFunctionCallSites, null))
+                }
+            }
+        }
+    }
+}
diff --git a/compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt b/compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt
new file mode 100644
index 00000000000..c5896c950a9
--- /dev/null
+++ b/compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt
@@ -0,0 +1,15 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+// FILE: 1.kt
+
+@file:JvmName("Facade")
+@file:JvmMultifileClass
+
+inline fun foo(o: String, k: String = "K", body: (String) -> String): String =
+    o + bar(body(k))
+
+fun bar(x: String): String = x
+
+// FILE: 2.kt
+
+fun box(): String = foo("O") { it }
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxInlineCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxInlineCodegenTestGenerated.java
index cbd6f92c991..354752321f5 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxInlineCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxInlineCodegenTestGenerated.java
@@ -1924,6 +1924,11 @@ public class BlackBoxInlineCodegenTestGenerated extends AbstractBlackBoxInlineCo
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxInline/multifileClasses"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("defaultArguments.kt")
+        public void testDefaultArguments() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt");
+        }
+
         @TestMetadata("inlineFromOptimizedMultifileClass.kt")
         public void testInlineFromOptimizedMultifileClass() throws Exception {
             runTest("compiler/testData/codegen/boxInline/multifileClasses/inlineFromOptimizedMultifileClass.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstInlineKotlinTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstInlineKotlinTestGenerated.java
index 653cee82a67..dcc6da5f24a 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstInlineKotlinTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstInlineKotlinTestGenerated.java
@@ -1924,6 +1924,11 @@ public class CompileKotlinAgainstInlineKotlinTestGenerated extends AbstractCompi
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxInline/multifileClasses"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("defaultArguments.kt")
+        public void testDefaultArguments() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt");
+        }
+
         @TestMetadata("inlineFromOptimizedMultifileClass.kt")
         public void testInlineFromOptimizedMultifileClass() throws Exception {
             runTest("compiler/testData/codegen/boxInline/multifileClasses/inlineFromOptimizedMultifileClass.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxInlineCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxInlineCodegenTestGenerated.java
index 13b6cbce34e..438a62e7260 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxInlineCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxInlineCodegenTestGenerated.java
@@ -1924,6 +1924,11 @@ public class IrBlackBoxInlineCodegenTestGenerated extends AbstractIrBlackBoxInli
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxInline/multifileClasses"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("defaultArguments.kt")
+        public void testDefaultArguments() throws Exception {
+            runTest("compiler/testData/codegen/boxInline/multifileClasses/defaultArguments.kt");
+        }
+
         @TestMetadata("inlineFromOptimizedMultifileClass.kt")
         public void testInlineFromOptimizedMultifileClass() throws Exception {
             runTest("compiler/testData/codegen/boxInline/multifileClasses/inlineFromOptimizedMultifileClass.kt");