diff --git a/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtils.hpp b/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtils.hpp
index 8ae61d9d173..be69191a189 100644
--- a/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtils.hpp
+++ b/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtils.hpp
@@ -52,14 +52,13 @@ MarkStats Mark(typename Traits::MarkQueue& markQueue) noexcept {
         stats.aliveHeapSetBytes += mm::GetAllocatedHeapSize(top);
 
         traverseReferredObjects(top, [&](ObjHeader* field) noexcept {
-            if (!isNullOrMarker(field) && field->heap()) {
+            if (field->heap()) {
                 Traits::enqueue(markQueue, field);
             }
         });
 
         if (auto* extraObjectData = mm::ExtraObjectData::Get(top)) {
-            auto weakCounter = extraObjectData->GetWeakReferenceCounter();
-            if (!isNullOrMarker(weakCounter)) {
+            if (auto weakCounter = extraObjectData->GetWeakReferenceCounter()) {
                 RuntimeAssert(
                         weakCounter->heap(), "Weak counter must be a heap object. object=%p counter=%p permanent=%d local=%d", top,
                         weakCounter, weakCounter->permanent(), weakCounter->local());
@@ -133,7 +132,7 @@ void collectRootSetForThread(typename Traits::MarkQueue& markQueue, mm::ThreadDa
             } else {
                 traverseReferredObjects(object, [&](ObjHeader* field) noexcept {
                     // Each permanent and stack object has own entry in the root set.
-                    if (field->heap() && !isNullOrMarker(field)) {
+                    if (field->heap()) {
                         Traits::enqueue(markQueue, field);
                     }
                 });
@@ -165,7 +164,7 @@ void collectRootSetGlobals(typename Traits::MarkQueue& markQueue) noexcept {
             } else {
                 traverseReferredObjects(object, [&](ObjHeader* field) noexcept {
                     // Each permanent and stack object has own entry in the root set.
-                    if (field->heap() && !isNullOrMarker(field)) {
+                    if (field->heap()) {
                         Traits::enqueue(markQueue, field);
                     }
                 });
diff --git a/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtilsMarkTest.cpp b/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtilsMarkTest.cpp
index c0bdb0e2ed1..d955e6dae9a 100644
--- a/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtilsMarkTest.cpp
+++ b/kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtilsMarkTest.cpp
@@ -227,7 +227,7 @@ TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleCharArray) {
 
 TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectWithInvalidFields) {
     Object object;
-    object->field1 = kInitializingSingleton;
+    object->field1 = nullptr;
 
     auto stats = Mark({object});
 
@@ -236,7 +236,7 @@ TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectWithInvalidFields) {
 
 TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectArrayWithInvalidFields) {
     ObjectArray array;
-    array.elements()[0] = kInitializingSingleton;
+    array.elements()[0] = nullptr;
 
     auto stats = Mark({array});
 
@@ -317,7 +317,7 @@ TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleCharArrayWithWeakCounter) {
 TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectWithInvalidFieldsWithWeakCounter) {
     Object weakCounter;
     Object object;
-    object->field1 = kInitializingSingleton;
+    object->field1 = nullptr;
     weakCounter->field1 = object.header();
     object.InstallWeakCounter(weakCounter);
 
@@ -329,7 +329,7 @@ TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectWithInvalidFieldsWithWeakCount
 TEST_F(MarkAndSweepUtilsMarkTest, MarkSingleObjectArrayWithInvalidFieldsWithWeakCounter) {
     Object weakCounter;
     ObjectArray array;
-    array.elements()[0] = kInitializingSingleton;
+    array.elements()[0] = nullptr;
     weakCounter->field1 = array.header();
     array.InstallWeakCounter(weakCounter);