diff --git a/mps/code/freelist.c b/mps/code/freelist.c
index c2d4ee1b623..6fc80733fbf 100644
--- a/mps/code/freelist.c
+++ b/mps/code/freelist.c
@@ -116,6 +116,7 @@ static void FreelistBlockSetLimit(Freelist fl, FreelistBlock block, Addr limit)
     AVER(size >= sizeof(block->small));
     block->small.next = FreelistTagSet(block->small.next);
   }
+  AVER(FreelistBlockLimit(block) == limit);
 }