diff --git a/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/diagnosticProvider/Fe10IdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java b/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/diagnosticProvider/Fe10IdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
index 25055bc88b9..32323919163 100644
--- a/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/diagnosticProvider/Fe10IdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
+++ b/analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/diagnosticProvider/Fe10IdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
@@ -82,6 +82,12 @@ public class Fe10IdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated ex
         runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/incompleteFor.kt");
     }
 
+    @Test
+    @TestMetadata("overrideProtectedClassReturnFromLibrary.kt")
+    public void testOverrideProtectedClassReturnFromLibrary() throws Exception {
+        runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt");
+    }
+
     @Test
     @TestMetadata("resolutionErrors.kt")
     public void testResolutionErrors() throws Exception {
diff --git a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/diagnosticProvider/FirIdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/diagnosticProvider/FirIdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
index ea516ec891f..7daf8911085 100644
--- a/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/diagnosticProvider/FirIdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
+++ b/analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/diagnosticProvider/FirIdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
@@ -82,6 +82,12 @@ public class FirIdeNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated ext
         runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/incompleteFor.kt");
     }
 
+    @Test
+    @TestMetadata("overrideProtectedClassReturnFromLibrary.kt")
+    public void testOverrideProtectedClassReturnFromLibrary() throws Exception {
+        runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt");
+    }
+
     @Test
     @TestMetadata("resolutionErrors.kt")
     public void testResolutionErrors() throws Exception {
diff --git a/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/diagnosticProvider/FirStandaloneNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java b/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/diagnosticProvider/FirStandaloneNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
index 8a1abaadf87..2fac339f0a7 100644
--- a/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/diagnosticProvider/FirStandaloneNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
+++ b/analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/diagnosticProvider/FirStandaloneNormalAnalysisSourceModuleCollectDiagnosticsTestGenerated.java
@@ -82,6 +82,12 @@ public class FirStandaloneNormalAnalysisSourceModuleCollectDiagnosticsTestGenera
         runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/incompleteFor.kt");
     }
 
+    @Test
+    @TestMetadata("overrideProtectedClassReturnFromLibrary.kt")
+    public void testOverrideProtectedClassReturnFromLibrary() throws Exception {
+        runTest("analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt");
+    }
+
     @Test
     @TestMetadata("resolutionErrors.kt")
     public void testResolutionErrors() throws Exception {
diff --git a/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt
new file mode 100644
index 00000000000..ca90c89e66a
--- /dev/null
+++ b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.kt
@@ -0,0 +1,16 @@
+// IGNORE_FE10
+// KT-64503
+
+// MODULE: lib
+// MODULE_KIND: LibraryBinary
+// FILE: TestExposeTypeLib.kt
+abstract class TestExposeTypeLib {
+    protected abstract fun returnProtectedClass(): ProtectedClass?
+    protected class ProtectedClass
+}
+
+// MODULE: main(lib)
+// FILE: usage.kt
+class Usage : TestExposeTypeLib() {
+    override fun returnProtectedClass(): ProtectedClass? = null
+}
diff --git a/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.standalone.fir.txt b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.standalone.fir.txt
new file mode 100644
index 00000000000..9f370a89565
--- /dev/null
+++ b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.standalone.fir.txt
@@ -0,0 +1 @@
+Diagnostics from elements:
diff --git a/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.txt b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.txt
new file mode 100644
index 00000000000..487620a431b
--- /dev/null
+++ b/analysis/analysis-api/testData/components/diagnosticsProvider/diagnostics/overrideProtectedClassReturnFromLibrary.txt
@@ -0,0 +1,4 @@
+Diagnostics from elements:
+  for PSI element of type KtNamedFunction at (15,5-64)
+    EXPOSED_FUNCTION_RETURN_TYPE      text ranges: [(103,123)]
+      PSI: KtNamedFunction at (15,5-64)