diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index dc4c600922df..8c537dfca881 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -2323,6 +2323,10 @@ exec_execute_message(const char *portal_name, long max_rows)
 			 * message.  The next protocol message will start a fresh timeout.
 			 */
 			disable_statement_timeout();
+
+			/* unnamed portal executed to completion, so close it */
+			if (portal_name[0] == '\0')
+				PortalDrop(portal, false);
 		}
 
 		/* Send appropriate CommandComplete to client */