diff --git "a/sdk/lib/rtl/heap.c" "b/sdk/lib/rtl/heap.c"
index b38f4c93e3b..fc0c9b5d541 100644
--- "a/sdk/lib/rtl/heap.c"
+++ "b/sdk/lib/rtl/heap.c"
@@ -1437,6 +1437,8 @@ RtlCreateHeap(ULONG Flags,
     NTSTATUS Status;
     ULONG MaxBlockSize;
 
+    if (Flags == HEAP_CLASS_1) Flags |= HEAP_GROWABLE;
+
     /* Check for a special heap */
     if (RtlpPageHeapEnabled && !Addr && !Lock)
     {