diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 7c87f012c3..a264a2edbc 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -246,14 +246,15 @@ ExecCloseIndices(ResultRelInfo *resultRelInfo)
 
 	for (i = 0; i < numIndices; i++)
 	{
-		if (indexDescs[i] == NULL)
-			continue;			/* shouldn't happen? */
+		Assert(indexDescs[i] != NULL);
 
 		/* Give the index a chance to do some post-insert cleanup */
 		index_insert_cleanup(indexDescs[i], indexInfos[i]);
 
 		/* Drop lock acquired by ExecOpenIndices */
 		index_close(indexDescs[i], RowExclusiveLock);
+
+		indexDescs[i] = NULL;
 	}
 
 	/*