diff --git a/src/memory/CopyingCollector.cpp b/src/memory/CopyingCollector.cpp
index e8c1cbc8..16eb6bf1 100644
--- a/src/memory/CopyingCollector.cpp
+++ b/src/memory/CopyingCollector.cpp
@@ -31,13 +31,13 @@ static gc_oop_t copy_if_necessary(gc_oop_t oop) {
         return (gc_oop_t) gcField;
     }
 
-    assert(GetHeap<HEAP_CLS>()->IsInOldBufferAndOldBufferIsValid(obj));
+    assert(GetHeap<CopyingHeap>()->IsInOldBufferAndOldBufferIsValid(obj));
     assert(!obj->IsMarkedInvalid());
 
     // we have to clone ourselves
     AbstractVMObject* newObj = obj->Clone();
 
-    assert(GetHeap<HEAP_CLS>()->IsInCurrentBuffer(newObj));
+    assert(GetHeap<CopyingHeap>()->IsInCurrentBuffer(newObj));
 
     // it looks to me like the Symbols get corrupted somehow, and when we try to clone them, it's too late
     // there are also waaaay too many symbols now.