diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 72a97b8b7a2..dd63c7e1296 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1236,6 +1236,13 @@ heap_drop_with_catalog(Oid relid)
 	 */
 	rel = relation_open(relid, AccessExclusiveLock);
 
+	/*
+	 * There can no longer be anyone *else* touching the relation, but we
+	 * might still have open queries or cursors, or pending trigger events,
+	 * in our own session.
+	 */
+	CheckTableNotInUse(rel, "DROP TABLE");
+
 	/*
 	 * Schedule unlinking of the relation's physical file at commit.
 	 */
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index e57809427af..dae3af322b9 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -848,6 +848,12 @@ index_drop(Oid indexId)
 
 	userIndexRelation = index_open(indexId, AccessExclusiveLock);
 
+	/*
+	 * There can no longer be anyone *else* touching the index, but we
+	 * might still have open queries using it in our own session.
+	 */
+	CheckTableNotInUse(userIndexRelation, "DROP INDEX");
+
 	/*
 	 * Schedule physical removal of the file
 	 */