diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
index bdfebc42273..614d70e68f4 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
@@ -23725,6 +23725,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                 runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasToSpecialAnnotation_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("actualTypealiasWithoutExpect.kt")
+            public void testActualTypealiasWithoutExpect() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt");
+            }
+
             @Test
             @TestMetadata("actualTypealias_defaultParamsIncompatibility.kt")
             public void testActualTypealias_defaultParamsIncompatibility() throws Exception {
@@ -23874,6 +23880,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                 runTest("compiler/testData/diagnostics/tests/multiplatform/expectTailrec_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("extraNestedClassOnActualViaActualTypealias.kt")
+            public void testExtraNestedClassOnActualViaActualTypealias() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt");
+            }
+
             @Test
             @TestMetadata("headerFunInNonHeaderClass.kt")
             public void testHeaderFunInNonHeaderClass() throws Exception {
@@ -23982,6 +23994,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                 runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.kt");
             }
 
+            @Test
+            @TestMetadata("nestedClassViaActualTypealiasIncompatibilities.kt")
+            public void testNestedClassViaActualTypealiasIncompatibilities() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt");
+            }
+
             @Test
             @TestMetadata("nestedClassViaActualTypealiasWithTypeParam.kt")
             public void testNestedClassViaActualTypealiasWithTypeParam() throws Exception {
diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
index 3b2cfa020eb..47c7560bcfa 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
@@ -23725,6 +23725,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                 runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasToSpecialAnnotation_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("actualTypealiasWithoutExpect.kt")
+            public void testActualTypealiasWithoutExpect() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt");
+            }
+
             @Test
             @TestMetadata("actualTypealias_defaultParamsIncompatibility.kt")
             public void testActualTypealias_defaultParamsIncompatibility() throws Exception {
@@ -23874,6 +23880,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                 runTest("compiler/testData/diagnostics/tests/multiplatform/expectTailrec_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("extraNestedClassOnActualViaActualTypealias.kt")
+            public void testExtraNestedClassOnActualViaActualTypealias() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt");
+            }
+
             @Test
             @TestMetadata("headerFunInNonHeaderClass.kt")
             public void testHeaderFunInNonHeaderClass() throws Exception {
@@ -23982,6 +23994,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                 runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.kt");
             }
 
+            @Test
+            @TestMetadata("nestedClassViaActualTypealiasIncompatibilities.kt")
+            public void testNestedClassViaActualTypealiasIncompatibilities() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt");
+            }
+
             @Test
             @TestMetadata("nestedClassViaActualTypealiasWithTypeParam.kt")
             public void testNestedClassViaActualTypealiasWithTypeParam() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java
index 9d3f353151f..fb7bc5d6d73 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java
@@ -86,6 +86,12 @@ public class FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated extends Abst
         runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasToSpecialAnnotation_oldLanguageVersion.kt");
     }
 
+    @Test
+    @TestMetadata("actualTypealiasWithoutExpect.kt")
+    public void testActualTypealiasWithoutExpect() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt");
+    }
+
     @Test
     @TestMetadata("actualTypealias_defaultParamsIncompatibility.kt")
     public void testActualTypealias_defaultParamsIncompatibility() throws Exception {
@@ -235,6 +241,12 @@ public class FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated extends Abst
         runTest("compiler/testData/diagnostics/tests/multiplatform/expectTailrec_oldLanguageVersion.kt");
     }
 
+    @Test
+    @TestMetadata("extraNestedClassOnActualViaActualTypealias.kt")
+    public void testExtraNestedClassOnActualViaActualTypealias() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt");
+    }
+
     @Test
     @TestMetadata("headerFunInNonHeaderClass.kt")
     public void testHeaderFunInNonHeaderClass() throws Exception {
@@ -343,6 +355,12 @@ public class FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated extends Abst
         runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.kt");
     }
 
+    @Test
+    @TestMetadata("nestedClassViaActualTypealiasIncompatibilities.kt")
+    public void testNestedClassViaActualTypealiasIncompatibilities() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt");
+    }
+
     @Test
     @TestMetadata("nestedClassViaActualTypealiasWithTypeParam.kt")
     public void testNestedClassViaActualTypealiasWithTypeParam() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java
index 8b49a2dc042..0b39feee2ca 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java
@@ -86,6 +86,12 @@ public class FirOldFrontendMPPDiagnosticsWithPsiTestGenerated extends AbstractFi
         runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasToSpecialAnnotation_oldLanguageVersion.kt");
     }
 
+    @Test
+    @TestMetadata("actualTypealiasWithoutExpect.kt")
+    public void testActualTypealiasWithoutExpect() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt");
+    }
+
     @Test
     @TestMetadata("actualTypealias_defaultParamsIncompatibility.kt")
     public void testActualTypealias_defaultParamsIncompatibility() throws Exception {
@@ -235,6 +241,12 @@ public class FirOldFrontendMPPDiagnosticsWithPsiTestGenerated extends AbstractFi
         runTest("compiler/testData/diagnostics/tests/multiplatform/expectTailrec_oldLanguageVersion.kt");
     }
 
+    @Test
+    @TestMetadata("extraNestedClassOnActualViaActualTypealias.kt")
+    public void testExtraNestedClassOnActualViaActualTypealias() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt");
+    }
+
     @Test
     @TestMetadata("headerFunInNonHeaderClass.kt")
     public void testHeaderFunInNonHeaderClass() throws Exception {
@@ -343,6 +355,12 @@ public class FirOldFrontendMPPDiagnosticsWithPsiTestGenerated extends AbstractFi
         runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.kt");
     }
 
+    @Test
+    @TestMetadata("nestedClassViaActualTypealiasIncompatibilities.kt")
+    public void testNestedClassViaActualTypealiasIncompatibilities() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt");
+    }
+
     @Test
     @TestMetadata("nestedClassViaActualTypealiasWithTypeParam.kt")
     public void testNestedClassViaActualTypealiasWithTypeParam() throws Exception {
diff --git a/compiler/ir/ir.actualization/src/main/kotlin/org/jetbrains/kotlin/backend/common/actualizer/ExpectActualCollector.kt b/compiler/ir/ir.actualization/src/main/kotlin/org/jetbrains/kotlin/backend/common/actualizer/ExpectActualCollector.kt
index 0106b7db9bc..94cc581507a 100644
--- a/compiler/ir/ir.actualization/src/main/kotlin/org/jetbrains/kotlin/backend/common/actualizer/ExpectActualCollector.kt
+++ b/compiler/ir/ir.actualization/src/main/kotlin/org/jetbrains/kotlin/backend/common/actualizer/ExpectActualCollector.kt
@@ -16,8 +16,7 @@ import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeAliasSymbol
 import org.jetbrains.kotlin.ir.types.IrTypeSystemContext
 import org.jetbrains.kotlin.ir.types.classifierOrFail
-import org.jetbrains.kotlin.ir.util.callableId
-import org.jetbrains.kotlin.ir.util.classIdOrFail
+import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.mpp.DeclarationSymbolMarker
 import org.jetbrains.kotlin.mpp.RegularClassSymbolMarker
@@ -61,8 +60,9 @@ internal class ExpectActualCollector(
     }
 
     private fun collectActualDeclarations(): ClassActualizationInfo {
+        val expectTopLevelClasses = ExpectTopLevelClassesCollector.collect(dependentFragments)
         val fragmentsWithActuals = dependentFragments.drop(1) + mainFragment
-        return ActualDeclarationsCollector.collectActualsFromFragments(fragmentsWithActuals)
+        return ActualDeclarationsCollector.collectActualsFromFragments(fragmentsWithActuals, expectTopLevelClasses)
     }
 
     private fun matchAllExpectDeclarations(
@@ -95,12 +95,36 @@ internal data class ClassActualizationInfo(
     }
 }
 
-
-
-private class ActualDeclarationsCollector {
+private class ExpectTopLevelClassesCollector {
     companion object {
-        fun collectActualsFromFragments(fragments: List<IrModuleFragment>): ClassActualizationInfo {
-            val collector = ActualDeclarationsCollector()
+        fun collect(fragments: List<IrModuleFragment>): Map<ClassId, IrClassSymbol> {
+            val collector = ExpectTopLevelClassesCollector()
+            collector.collect(fragments)
+            return collector.expectTopLevelClasses
+        }
+    }
+
+    private val expectTopLevelClasses = mutableMapOf<ClassId, IrClassSymbol>()
+
+    fun collect(fragments: List<IrModuleFragment>) {
+        for (fragment in fragments) {
+            for (file in fragment.files) {
+                for (declaration in file.declarations) {
+                    if (declaration is IrClass && declaration.isExpect && declaration.isTopLevel) {
+                        expectTopLevelClasses[declaration.classIdOrFail] = declaration.symbol
+                    }
+                }
+            }
+        }
+    }
+}
+
+private class ActualDeclarationsCollector(
+    private val expectTopLevelClasses: Map<ClassId, IrClassSymbol>,
+) {
+    companion object {
+        fun collectActualsFromFragments(fragments: List<IrModuleFragment>, expectTopLevelClasses: Map<ClassId, IrClassSymbol>): ClassActualizationInfo {
+            val collector = ActualDeclarationsCollector(expectTopLevelClasses)
             for (fragment in fragments) {
                 collector.collect(fragment)
             }
@@ -146,6 +170,7 @@ private class ActualDeclarationsCollector {
                 actualSymbolsToFile[element.symbol] = currentFile
 
                 collect(expandedTypeSymbol.owner)
+                recordMappingsForNestedClassesActualizedViaTypealias(classId, expandedTypeSymbol)
             }
             is IrClass -> {
                 if (element.isExpect || !visitedActualClasses.add(element)) return
@@ -175,6 +200,28 @@ private class ActualDeclarationsCollector {
         }
     }
 
+    /**
+     * For given actual typealias goes through all nested classes in expect class to record their mappings in [actualClasses].
+     *
+     * This is needed because in case of `expect` nested classes actualized via typealias we can't simply find actual symbol by
+     * `expect` `ClassId` (like we do for top-level classes), because `ClassId` is different.
+     * For example, `expect` class `com/example/ExpectClass.Nested` may have actual with id `real/package/ActualTypeliasTarget.Nested`.
+     */
+    private fun recordMappingsForNestedClassesActualizedViaTypealias(typealiasClassId: ClassId, actualClassSymbol: IrClassSymbol) {
+        fun recordRecursively(expectClass: IrClass, actualClass: IrClass) {
+            val actualNestedClassesByName = actualClass.nestedClasses.associateBy { it.name }
+
+            for (expectNestedClass in expectClass.nestedClasses) {
+                val actualNestedClass = actualNestedClassesByName[expectNestedClass.name] ?: continue
+                actualClasses[expectNestedClass.classIdOrFail] = actualNestedClass.symbol
+                recordRecursively(expectNestedClass, actualNestedClass)
+            }
+        }
+
+        val expectClassSymbol = expectTopLevelClasses[typealiasClassId] ?: return
+        recordRecursively(expectClassSymbol.owner, actualClassSymbol.owner)
+    }
+
     private fun recordActualCallable(callableDeclaration: IrDeclarationWithName, callableId: CallableId) {
         if (callableId.classId == null) {
             actualTopLevels
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
index d856ca6e2c7..04d3a96245c 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
@@ -259,6 +259,11 @@ val IrClassSymbol.constructors: Sequence<IrConstructorSymbol>
 val IrClass.fields: Sequence<IrField>
     get() = declarations.asSequence().filterIsInstance<IrField>()
 
+// This declaration accesses IrDeclarationContainer.declarations, which is marked with this opt-in
+@UnsafeDuringIrConstructionAPI
+val IrClass.nestedClasses: Sequence<IrClass>
+    get() = declarations.asSequence().filterIsInstance<IrClass>()
+
 // This declaration accesses IrDeclarationContainer.declarations, which is marked with this opt-in
 @UnsafeDuringIrConstructionAPI
 val IrClassSymbol.fields: Sequence<IrFieldSymbol>
diff --git a/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.fir.kt
index ff8141f8f02..b51ac1693cc 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.fir.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.fir.kt
@@ -16,5 +16,5 @@ annotation class AnnImpl {
 
 actual typealias Ann = AnnImpl
 
-<!ACTUAL_ANNOTATIONS_NOT_MATCH_EXPECT!>@AnnImpl.Nested
-actual fun foo() {}<!>
+@AnnImpl.Nested
+actual fun foo() {}
diff --git a/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.ll.kt
deleted file mode 100644
index b51ac1693cc..00000000000
--- a/compiler/testData/diagnostics/tests/multiplatform/actualAnnotationsNotMatchExpect/nestedAnnotationClassViaActualTypeAlias.ll.kt
+++ /dev/null
@@ -1,20 +0,0 @@
-// MODULE: m1-common
-// FILE: common.kt
-
-expect annotation class Ann() {
-    annotation class Nested()
-}
-
-@Ann.Nested
-expect fun foo()
-
-// MODULE: m1-jvm()()(m1-common)
-// FILE: jvm.kt
-annotation class AnnImpl {
-    annotation class Nested
-}
-
-actual typealias Ann = AnnImpl
-
-@AnnImpl.Nested
-actual fun foo() {}
diff --git a/compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt b/compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt
new file mode 100644
index 00000000000..325433e274d
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt
@@ -0,0 +1,9 @@
+// FIR_IDENTICAL
+// MODULE: m1-common
+// FILE: common.kt
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+class FooImpl
+
+actual typealias <!ACTUAL_WITHOUT_EXPECT!>Foo<!> = FooImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.fir.kt
index 17159c91509..c5b334d304f 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.fir.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.fir.kt
@@ -23,5 +23,5 @@ class FooImpl {
 actual typealias Foo = FooImpl
 
 actual annotation class Ann(
-    actual val p: KClass<*> = <!ACTUAL_ANNOTATION_CONFLICTING_DEFAULT_ARGUMENT_VALUE!>FooImpl.Nested::class<!>
+    actual val p: KClass<*> = FooImpl.Nested::class
 )
diff --git a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.ll.kt
deleted file mode 100644
index c5b334d304f..00000000000
--- a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/annotationDefaultArgKclassWithNestedClassViaActualTypeAlias.ll.kt
+++ /dev/null
@@ -1,27 +0,0 @@
-// MODULE: m1-common
-// FILE: common.kt
-
-import kotlin.reflect.KClass
-
-expect annotation class Ann(
-    val p: KClass<*> = Foo.Nested::class
-)
-
-expect class Foo {
-    class Nested
-}
-
-// MODULE: m2-jvm()()(m1-common)
-// FILE: jvm.kt
-
-import kotlin.reflect.KClass
-
-class FooImpl {
-    class Nested
-}
-
-actual typealias Foo = FooImpl
-
-actual annotation class Ann(
-    actual val p: KClass<*> = FooImpl.Nested::class
-)
diff --git a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.fir.kt
index 7643467e5de..ccb28e47fc8 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.fir.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.fir.kt
@@ -1,8 +1,8 @@
 // MODULE: m1-common
 // FILE: common.kt
-<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>expect class DefaultArgsInNestedClass {
-    <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>annotation class Nested<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>(val p: String = "")<!><!>
-}<!>
+expect class DefaultArgsInNestedClass {
+    annotation class Nested(val p: String = "")
+}
 
 // MODULE: m2-jvm()()(m1-common)
 // FILE: jvm.kt
@@ -10,5 +10,5 @@ class DefaultArgsInNestedClassImpl {
     annotation class Nested(val p: String = "")
 }
 
-// Incompatible because of bug KT-31636
+// Incompatible in K1 because of bug KT-31636
 actual typealias DefaultArgsInNestedClass = DefaultArgsInNestedClassImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.kt b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.kt
index f6788ba54e0..775d4c47379 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.kt
@@ -10,5 +10,5 @@ class DefaultArgsInNestedClassImpl {
     annotation class Nested(val p: String = "")
 }
 
-// Incompatible because of bug KT-31636
+// Incompatible in K1 because of bug KT-31636
 actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>DefaultArgsInNestedClass<!> = DefaultArgsInNestedClassImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.ll.kt
deleted file mode 100644
index f6788ba54e0..00000000000
--- a/compiler/testData/diagnostics/tests/multiplatform/defaultArguments/nestedAnnotationClassViaActualTypealias.ll.kt
+++ /dev/null
@@ -1,14 +0,0 @@
-// MODULE: m1-common
-// FILE: common.kt
-expect class DefaultArgsInNestedClass {
-    annotation class Nested(val p: String = "")
-}
-
-// MODULE: m2-jvm()()(m1-common)
-// FILE: jvm.kt
-class DefaultArgsInNestedClassImpl {
-    annotation class Nested(val p: String = "")
-}
-
-// Incompatible because of bug KT-31636
-actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>DefaultArgsInNestedClass<!> = DefaultArgsInNestedClassImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt
similarity index 58%
rename from compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.ll.kt
rename to compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt
index e4e7d4239bd..74be549fddd 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.ll.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt
@@ -1,17 +1,15 @@
+// FIR_IDENTICAL
 // MODULE: m1-common
 // FILE: common.kt
 expect class Foo {
-    class Inner {
-        fun foo(p: List<Inner>)
-    }
+    class Inner
 }
 
 // MODULE: m2-jvm()()(m1-common)
 // FILE: jvm.kt
 class FooImpl {
-    class Inner {
-        fun foo(p: List<Inner>) {}
-    }
+    class Inner
+    class Extra
 }
 
 actual typealias Foo = FooImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.fir.kt
index 9734e9a47e0..663e2eb8e39 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.fir.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.fir.kt
@@ -1,16 +1,16 @@
 // MODULE: m1-common
 // FILE: common.kt
-<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>expect class Foo {
-    <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>class Inner<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>()<!><!>
-}<!>
+expect class Foo {
+    class Inner()
+}
 
-<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>expect class SeveralInner {
-    <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>class Inner1 {
-        <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>class Inner2 {
-            <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>class Inner3<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>()<!><!>
-        }<!>
-    }<!>
-}<!>
+expect class SeveralInner {
+    class Inner1 {
+        class Inner2 {
+            class Inner3()
+        }
+    }
+}
 
 // MODULE: m2-jvm()()(m1-common)
 // FILE: jvm.kt
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.ll.kt
deleted file mode 100644
index 663e2eb8e39..00000000000
--- a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealias.ll.kt
+++ /dev/null
@@ -1,31 +0,0 @@
-// MODULE: m1-common
-// FILE: common.kt
-expect class Foo {
-    class Inner()
-}
-
-expect class SeveralInner {
-    class Inner1 {
-        class Inner2 {
-            class Inner3()
-        }
-    }
-}
-
-// MODULE: m2-jvm()()(m1-common)
-// FILE: jvm.kt
-class FooImpl {
-    class Inner
-}
-
-actual typealias Foo = FooImpl
-
-class SeveralInnerImpl {
-    class Inner1 {
-        class Inner2 {
-            class Inner3
-        }
-    }
-}
-
-actual typealias SeveralInner = SeveralInnerImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.fir.kt
index 5f968715587..e4e7d4239bd 100644
--- a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.fir.kt
+++ b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.fir.kt
@@ -1,10 +1,10 @@
 // MODULE: m1-common
 // FILE: common.kt
-<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>expect class Foo {
-    <!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>class Inner {
-        <!EXPECT_ACTUAL_MISMATCH{JVM}!>fun foo(p: List<Inner>)<!>
-    }<!>
-}<!>
+expect class Foo {
+    class Inner {
+        fun foo(p: List<Inner>)
+    }
+}
 
 // MODULE: m2-jvm()()(m1-common)
 // FILE: jvm.kt
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.fir.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.fir.kt
new file mode 100644
index 00000000000..43c034ec17b
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.fir.kt
@@ -0,0 +1,14 @@
+// MODULE: m1-common()()()
+// FILE: common.kt
+<!EXPECT_ACTUAL_INCOMPATIBILITY{JVM}!>expect class Foo {
+    class Inner
+    <!NO_ACTUAL_FOR_EXPECT{JVM}!>class AbsentOnactual<!>
+}<!>
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+class FooImpl {
+    class Inner
+}
+
+actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Foo<!> = FooImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt
new file mode 100644
index 00000000000..da1738b336a
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt
@@ -0,0 +1,14 @@
+// MODULE: m1-common()()()
+// FILE: common.kt
+expect class Foo {
+    class Inner
+    class AbsentOnactual
+}
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+class FooImpl {
+    class Inner
+}
+
+actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Foo<!> = FooImpl
diff --git a/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.ll.kt b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.ll.kt
new file mode 100644
index 00000000000..da1738b336a
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.ll.kt
@@ -0,0 +1,14 @@
+// MODULE: m1-common()()()
+// FILE: common.kt
+expect class Foo {
+    class Inner
+    class AbsentOnactual
+}
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+class FooImpl {
+    class Inner
+}
+
+actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Foo<!> = FooImpl
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
index 9975bae8a54..4d5c97878cd 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
@@ -23725,6 +23725,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasToSpecialAnnotation_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("actualTypealiasWithoutExpect.kt")
+            public void testActualTypealiasWithoutExpect() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/actualTypealiasWithoutExpect.kt");
+            }
+
             @Test
             @TestMetadata("actualTypealias_defaultParamsIncompatibility.kt")
             public void testActualTypealias_defaultParamsIncompatibility() throws Exception {
@@ -23874,6 +23880,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/expectTailrec_oldLanguageVersion.kt");
             }
 
+            @Test
+            @TestMetadata("extraNestedClassOnActualViaActualTypealias.kt")
+            public void testExtraNestedClassOnActualViaActualTypealias() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/extraNestedClassOnActualViaActualTypealias.kt");
+            }
+
             @Test
             @TestMetadata("headerFunInNonHeaderClass.kt")
             public void testHeaderFunInNonHeaderClass() throws Exception {
@@ -23982,6 +23994,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasExpandInTypeParam.kt");
             }
 
+            @Test
+            @TestMetadata("nestedClassViaActualTypealiasIncompatibilities.kt")
+            public void testNestedClassViaActualTypealiasIncompatibilities() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/nestedClassViaActualTypealiasIncompatibilities.kt");
+            }
+
             @Test
             @TestMetadata("nestedClassViaActualTypealiasWithTypeParam.kt")
             public void testNestedClassViaActualTypealiasWithTypeParam() throws Exception {