diff --git a/src/heap/cppgc-js/unified-heap-marking-state-inl.h b/src/heap/cppgc-js/unified-heap-marking-state-inl.h
index fd4d7cf97f..888bbd0c43 100644
--- a/src/heap/cppgc-js/unified-heap-marking-state-inl.h
+++ b/src/heap/cppgc-js/unified-heap-marking-state-inl.h
@@ -46,7 +46,6 @@ void UnifiedHeapMarkingState::MarkAndPush(
     return;
   }
   HeapObject heap_object = HeapObject::cast(object);
-  if (heap_object.InReadOnlySpace()) return;
   if (marking_state_->WhiteToGrey(heap_object)) {
     local_marking_worklist_->Push(heap_object);
   }
diff --git a/src/heap/marking-barrier-inl.h b/src/heap/marking-barrier-inl.h
index b1eea01acc..4a9761abd4 100644
--- a/src/heap/marking-barrier-inl.h
+++ b/src/heap/marking-barrier-inl.h
@@ -70,7 +70,6 @@ void MarkingBarrier::MarkValueShared(HeapObject value) {
 }
 
 void MarkingBarrier::MarkValueLocal(HeapObject value) {
-  DCHECK(!value.InReadOnlySpace());
   if (is_minor()) {
     // We do not need to insert into RememberedSet<OLD_TO_NEW> here because the
     // C++ marking barrier already does this for us.
diff --git a/src/heap/marking-barrier.cc b/src/heap/marking-barrier.cc
index 9ce722b47a..5a31efd1d1 100644
--- a/src/heap/marking-barrier.cc
+++ b/src/heap/marking-barrier.cc
@@ -60,7 +60,7 @@ void MarkingBarrier::WriteWithoutHost(HeapObject value) {
       return;
     }
   }
-  if (value.InReadOnlySpace()) return;
+
   MarkValueLocal(value);
 }