diff --git a/lib/IRGen/TypeLayout.cpp b/lib/IRGen/TypeLayout.cpp
index f7660b8833fa5..b5201c123d5f3 100644
--- a/lib/IRGen/TypeLayout.cpp
+++ b/lib/IRGen/TypeLayout.cpp
@@ -1295,14 +1295,14 @@ bool ScalarTypeLayoutEntry::refCountString(IRGenModule &IGM,
     B.addRefCount(LayoutStringBuilder::RefCountingKind::Block, size);
     break;
   case ScalarKind::ObjCReference: {
-    auto *classTI = dyn_cast<ClassTypeInfo>(&typeInfo);
-    assert(classTI);
-    if (!classTI->getClass()->hasClangNode()) {
-      B.addRefCount(LayoutStringBuilder::RefCountingKind::NativeSwiftObjC,
-                    size);
-    } else {
-      B.addRefCount(LayoutStringBuilder::RefCountingKind::ObjC, size);
+    if (auto *classDecl = representative.getClassOrBoundGenericClass()) {
+      if (!classDecl->hasClangNode()) {
+        B.addRefCount(LayoutStringBuilder::RefCountingKind::NativeSwiftObjC,
+                      size);
+        break;
+      }
     }
+    B.addRefCount(LayoutStringBuilder::RefCountingKind::ObjC, size);
     break;
   }
   case ScalarKind::ThickFunc:
diff --git a/test/Interpreter/layout_string_witnesses_objc.swift b/test/Interpreter/layout_string_witnesses_objc.swift
index 04870c97bd28a..5f49b7169e40a 100644
--- a/test/Interpreter/layout_string_witnesses_objc.swift
+++ b/test/Interpreter/layout_string_witnesses_objc.swift
@@ -190,3 +190,103 @@ func testMultiPayloadBlock() {
 }
 
 testMultiPayloadBlock()
+
+class GenericOuterClassNSObject<T: NSObject> {
+    enum InnerEnum {
+        case x(T.Type)
+        case y(T)
+    }
+}
+
+func testNestedGenericEnumNSObject() {
+    let ptr = UnsafeMutablePointer<GenericOuterClassNSObject<ObjCPrintOnDealloc>.InnerEnum>.allocate(capacity: 1)
+
+    // initWithCopy
+    do {
+        let x = GenericOuterClassNSObject<ObjCPrintOnDealloc>.InnerEnum.y(ObjCPrintOnDealloc())
+        testInit(ptr, to: x)
+    }
+
+    // assignWithTake
+    do {
+        let y = GenericOuterClassNSObject<ObjCPrintOnDealloc>.InnerEnum.y(ObjCPrintOnDealloc())
+
+        // CHECK-NEXT: Before deinit
+        print("Before deinit")
+
+        // CHECK-NEXT: ObjCPrintOnDealloc deinitialized!
+        testAssign(ptr, from: y)
+    }
+
+    // assignWithCopy
+    do {
+        var z = GenericOuterClassNSObject<ObjCPrintOnDealloc>.InnerEnum.y(ObjCPrintOnDealloc())
+
+        // CHECK-NEXT: Before deinit
+        print("Before deinit")
+
+        // CHECK-NEXT: ObjCPrintOnDealloc deinitialized!
+        testAssignCopy(ptr, from: &z)
+    }
+
+    // CHECK-NEXT: Before deinit
+    print("Before deinit")
+
+    // destroy
+    // CHECK-NEXT: ObjCPrintOnDealloc deinitialized!
+    testDestroy(ptr)
+
+    ptr.deallocate()
+}
+
+testNestedGenericEnumNSObject()
+
+class GenericOuterClassSwiftObjC<T: SwiftObjC> {
+    enum InnerEnum {
+        case x(T.Type)
+        case y(T)
+    }
+}
+
+func testNestedGenericEnumSwiftObjC() {
+    let ptr = UnsafeMutablePointer<GenericOuterClassSwiftObjC<SwiftObjC>.InnerEnum>.allocate(capacity: 1)
+
+    // initWithCopy
+    do {
+        let x = GenericOuterClassSwiftObjC<SwiftObjC>.InnerEnum.y(SwiftObjC())
+        testInit(ptr, to: x)
+    }
+
+    // assignWithTake
+    do {
+        let y = GenericOuterClassSwiftObjC<SwiftObjC>.InnerEnum.y(SwiftObjC())
+
+        // CHECK-NEXT: Before deinit
+        print("Before deinit")
+
+        // CHECK-NEXT: SwiftObjC deinitialized!
+        testAssign(ptr, from: y)
+    }
+
+    // assignWithCopy
+    do {
+        var z = GenericOuterClassSwiftObjC<SwiftObjC>.InnerEnum.y(SwiftObjC())
+
+        // CHECK-NEXT: Before deinit
+        print("Before deinit")
+
+        // CHECK-NEXT: SwiftObjC deinitialized!
+        testAssignCopy(ptr, from: &z)
+    }
+
+    // CHECK-NEXT: Before deinit
+    print("Before deinit")
+
+    // destroy
+    // CHECK-NEXT: SwiftObjC deinitialized!
+    testDestroy(ptr)
+
+    ptr.deallocate()
+}
+
+testNestedGenericEnumSwiftObjC()