diff --git a/src/backend/access/heap/visibilitymap.c b/src/backend/access/heap/visibilitymap.c
index 74ff01bb17..e193682352 100644
--- a/src/backend/access/heap/visibilitymap.c
+++ b/src/backend/access/heap/visibilitymap.c
@@ -259,9 +259,9 @@ visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
 
 	Assert(InRecovery || XLogRecPtrIsInvalid(recptr));
 	Assert(InRecovery || PageIsAllVisible((Page) BufferGetPage(heapBuf)));
+	Assert((flags & VISIBILITYMAP_VALID_BITS) == flags);
 
 	/* Must never set all_frozen bit without also setting all_visible bit */
-	Assert(flags & VISIBILITYMAP_VALID_BITS);
 	Assert(flags != VISIBILITYMAP_ALL_FROZEN);
 
 	/* Check that we have the right heap page pinned, if present */