diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/MemoizedInlineClassReplacements.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/MemoizedInlineClassReplacements.kt
index f5c4e2bdc88..221047a9193 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/MemoizedInlineClassReplacements.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/MemoizedInlineClassReplacements.kt
@@ -151,12 +151,15 @@ class MemoizedInlineClassReplacements {
                 val name = if (parameter == function.extensionReceiverParameter) Name.identifier("\$receiver") else parameter.name
                 val newParameter: IrValueParameter
                 if (parameter == function.dispatchReceiverParameter) {
-                    newParameter = parameter.copyTo(this, index = -1, name = name)
+                    newParameter = parameter.copyTo(this, index = -1, name = name, defaultValue = null)
                     dispatchReceiverParameter = newParameter
                 } else {
-                    newParameter = parameter.copyTo(this, index = index - 1, name = name)
+                    newParameter = parameter.copyTo(this, index = index - 1, name = name, defaultValue = null)
                     valueParameters.add(newParameter)
                 }
+                // Assuming that constructors and non-override functions are always replaced with the unboxed
+                // equivalent, deep-copying the value here is unnecessary. See `JvmInlineClassLowering`.
+                newParameter.defaultValue = parameter.defaultValue
                 parameterMap[parameter.symbol] = newParameter
             }
         }
@@ -176,8 +179,10 @@ class MemoizedInlineClassReplacements {
                     else -> parameter.name
                 }
 
-                val newParameter = parameter.copyTo(this, index = index, name = name)
+                val newParameter = parameter.copyTo(this, index = index, name = name, defaultValue = null)
                 valueParameters.add(newParameter)
+                // See comment next to a similar line above.
+                newParameter.defaultValue = parameter.defaultValue
                 parameterMap[parameter.symbol] = newParameter
             }
         }
diff --git a/compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt b/compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt
new file mode 100644
index 00000000000..8cfdc95d292
--- /dev/null
+++ b/compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt
@@ -0,0 +1,9 @@
+// !LANGUAGE: +InlineClasses
+// IGNORE_BACKEND_FIR: JVM_IR
+// FILE: a.kt
+fun box() = A(0).f()
+
+// FILE: b.kt
+inline class A(val i: Int)
+
+fun A.f(xs: Array<String> = Array<String>(1) { "OK" }) = xs[i]
diff --git a/compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt b/compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt
new file mode 100644
index 00000000000..17904c6a0e8
--- /dev/null
+++ b/compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt
@@ -0,0 +1,11 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// TARGET_BACKEND: JVM
+// WITH_REFLECT
+
+import kotlin.reflect.jvm.reflect
+
+inline class C(val x: Int)
+
+fun C.f(x: (String) -> Unit = { OK: String -> }) = x.reflect()?.parameters?.singleOrNull()?.name
+
+fun box(): String = C(0).f() ?: "null"
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
index a48967fbf0b..4f5f8d76903 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
@@ -12731,6 +12731,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");
@@ -23900,6 +23905,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/parameterNamesAndNullability.kt");
             }
 
+            @TestMetadata("reflectOnDefaultWithInlineClassArgument.kt")
+            public void testReflectOnDefaultWithInlineClassArgument() throws Exception {
+                runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt");
+            }
+
             @TestMetadata("reflectOnLambdaInField.kt")
             public void testReflectOnLambdaInField() throws Exception {
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnLambdaInField.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
index d82a114823b..e46d9e4bd8d 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
@@ -12746,6 +12746,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java
index 3569bc06828..8b8ef7931a0 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java
@@ -11581,6 +11581,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");
@@ -22384,6 +22389,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/parameterNamesAndNullability.kt");
             }
 
+            @TestMetadata("reflectOnDefaultWithInlineClassArgument.kt")
+            public void testReflectOnDefaultWithInlineClassArgument() throws Exception {
+                runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt");
+            }
+
             @TestMetadata("reflectOnLambdaInField.kt")
             public void testReflectOnLambdaInField() throws Exception {
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnLambdaInField.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
index 7582b6585f8..39b4c4b2767 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
@@ -11581,6 +11581,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");
@@ -22384,6 +22389,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/parameterNamesAndNullability.kt");
             }
 
+            @TestMetadata("reflectOnDefaultWithInlineClassArgument.kt")
+            public void testReflectOnDefaultWithInlineClassArgument() throws Exception {
+                runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnDefaultWithInlineClassArgument.kt");
+            }
+
             @TestMetadata("reflectOnLambdaInField.kt")
             public void testReflectOnLambdaInField() throws Exception {
                 runTest("compiler/testData/codegen/box/reflection/lambdaClasses/reflectOnLambdaInField.kt");
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java
index 221dfe0dee2..68679a3f046 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java
@@ -10001,6 +10001,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
index 665a6397c0d..45ba8d74b19 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
@@ -11141,6 +11141,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/inlineClasses/defaultFunctionsFromAnyForInlineClass.kt");
         }
 
+        @TestMetadata("defaultWithInlineClassArgument.kt")
+        public void testDefaultWithInlineClassArgument() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/defaultWithInlineClassArgument.kt");
+        }
+
         @TestMetadata("elvisWithInlineClassAndNullConstant.kt")
         public void testElvisWithInlineClassAndNullConstant() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/elvisWithInlineClassAndNullConstant.kt");