2 files changed, 2 insertions, 1 deletions
diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index ad4ecfe76d..5aaf710ee8 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -234,7 +234,7 @@ bool sweepChunk(MemoryManager::Data::ChunkHeader *header, uint *itemsInUse, Exec
                     m->_checkIsDestroyed();
                 }
 
-                memset(m, 0, header->itemSize);
+                memset(m, 0, sizeof(Heap::Base));
 #ifdef V4_USE_VALGRIND
                 VALGRIND_DISABLE_ERROR_REPORTING;
                 VALGRIND_MEMPOOL_FREE(engine->memoryManager, m);
diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index e68fc07a46..dfa0d85dff 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -111,6 +111,7 @@ public:
         V4_ASSERT_IS_TRIVIAL(typename ManagedType::Data)
         size = align(size);
         Heap::Base *o = allocData(size, unmanagedSize);
+        memset(o, 0, size);
         o->setVtable(ManagedType::staticVTable());
         return static_cast<typename ManagedType::Data *>(o);
     }