diff --git a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java
index a47d38a4c57..d18e9443e60 100644
--- a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java
+++ b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java
@@ -34116,6 +34116,12 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Test
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
diff --git a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java
index e31fd686243..74e56d6e4f0 100644
--- a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java
+++ b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java
@@ -34116,6 +34116,12 @@ public class FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Test
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
diff --git a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java
index de2df69c1c5..f173d7c0df4 100644
--- a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java
+++ b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java
@@ -34116,6 +34116,12 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Test
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrActualizer.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrActualizer.kt
index 15eeddf895e..29c80807aab 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrActualizer.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrActualizer.kt
@@ -119,7 +119,9 @@ object IrActualizer {
     }
 
     private fun mergeIrFragments(mainFragment: IrModuleFragment, dependentFragments: List<IrModuleFragment>) {
-        mainFragment.files.addAll(0, dependentFragments.flatMap { it.files })
+        val newFiles = dependentFragments.flatMap { it.files }
+        for (file in newFiles) file.module = mainFragment
+        mainFragment.files.addAll(0, newFiles)
     }
 }
 
diff --git a/compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt b/compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt
new file mode 100644
index 00000000000..91b41eae61c
--- /dev/null
+++ b/compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt
@@ -0,0 +1,47 @@
+// LANGUAGE: +MultiPlatformProjects
+// It accidentially passes K1 JVM while not intended to do so.
+// IGNORE_BACKEND_K1: JS, JS_IR, JS_IR_ES6, WASM, NATIVE
+// MODULE: common
+// FILE: common.kt
+
+open class A {
+    open internal fun foo() = "A"
+}
+
+open class B {
+    open internal fun foo() = "B"
+}
+
+
+// MODULE: middle()()(common)
+// FILE: middle.kt
+
+class AChild : A() {
+    override public fun foo() = "AChild"
+}
+
+open class C {
+    open internal fun foo() = "C"
+}
+
+// MODULE: main()()(middle)
+// FILE: main.kt
+
+class BChild : B() {
+    override public fun foo() = "BChild"
+}
+
+class CChild : C() {
+    override public fun foo() = "CChild"
+}
+
+
+fun box() : String {
+    val a: A = AChild()
+    val b: B = BChild()
+    val c: C = CChild()
+    if (a.foo() != "AChild") return "Fail 1"
+    if (b.foo() != "BChild") return "Fail 2"
+    if (c.foo() != "CChild") return "Fail 3"
+    return "OK"
+}
\ No newline at end of file
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
index 10bac06bf26..13003c7e91f 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
@@ -32394,6 +32394,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
index bce20c2d85c..845d51b8b26 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
@@ -34116,6 +34116,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Test
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java
index 19253285129..5d566916e95 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java
@@ -34116,6 +34116,12 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Test
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
diff --git a/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java b/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
index 3eac74df76a..833e9be4e5d 100644
--- a/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
+++ b/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
@@ -29071,6 +29071,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClassJVM.kt");
             }
 
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @TestMetadata("javaMethodWithTypeParameter.kt")
             public void testJavaMethodWithTypeParameter() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/k2/javaMethodWithTypeParameter.kt");
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java
index 3754ccfdb71..4628ed0cdc1 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java
@@ -23820,6 +23820,12 @@ public class FirJsCodegenBoxTestGenerated extends AbstractFirJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java
index 7658b87984b..ed64900422c 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java
@@ -23820,6 +23820,12 @@ public class FirJsES6CodegenBoxTestGenerated extends AbstractFirJsES6CodegenBoxT
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
index 06dbde514e0..5a844e6bf0e 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
@@ -23820,6 +23820,12 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java
index 4ea710ae421..4bb0e64264f 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java
@@ -23820,6 +23820,12 @@ public class IrJsES6CodegenBoxTestGenerated extends AbstractIrJsES6CodegenBoxTes
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java
index af17d5e1e20..a1bfce76121 100644
--- a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java
+++ b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java
@@ -26789,6 +26789,12 @@ public class FirNativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTe
                     runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
                 }
 
+                @Test
+                @TestMetadata("internalOverride.kt")
+                public void testInternalOverride() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+                }
+
                 @Nested
                 @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
                 @TestDataPath("$PROJECT_ROOT")
diff --git a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java
index 59c9412797d..5dc827b8f35 100644
--- a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java
+++ b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java
@@ -27405,6 +27405,12 @@ public class FirNativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenB
                     runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
                 }
 
+                @Test
+                @TestMetadata("internalOverride.kt")
+                public void testInternalOverride() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+                }
+
                 @Nested
                 @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
                 @TestDataPath("$PROJECT_ROOT")
diff --git a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java
index 086d7a66eb1..536b38386b7 100644
--- a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java
+++ b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java
@@ -26482,6 +26482,12 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                     runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
                 }
 
+                @Test
+                @TestMetadata("internalOverride.kt")
+                public void testInternalOverride() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+                }
+
                 @Nested
                 @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
                 @TestDataPath("$PROJECT_ROOT")
diff --git a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java
index 95f72156666..147b7168078 100644
--- a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java
+++ b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java
@@ -26790,6 +26790,12 @@ public class NativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenBoxT
                     runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
                 }
 
+                @Test
+                @TestMetadata("internalOverride.kt")
+                public void testInternalOverride() throws Exception {
+                    runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+                }
+
                 @Nested
                 @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
                 @TestDataPath("$PROJECT_ROOT")
diff --git a/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java b/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java
index 9d95455842e..5f82cc72590 100644
--- a/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java
+++ b/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java
@@ -23568,6 +23568,12 @@ public class FirWasmCodegenBoxTestGenerated extends AbstractFirWasmCodegenBoxTes
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")
diff --git a/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java b/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java
index ecb7cbf3486..38c8da12bf1 100644
--- a/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java
+++ b/wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java
@@ -23568,6 +23568,12 @@ public class K1WasmCodegenBoxTestGenerated extends AbstractK1WasmCodegenBoxTest
                 runTest("compiler/testData/codegen/box/multiplatform/k2/expectValInInlineClass.kt");
             }
 
+            @Test
+            @TestMetadata("internalOverride.kt")
+            public void testInternalOverride() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/k2/internalOverride.kt");
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/multiplatform/k2/annotations")
             @TestDataPath("$PROJECT_ROOT")