diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 1efc22559d9..8b3b1bf91ec 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -3990,6 +3990,7 @@ append_depends_on_extension(Archive *fout,
 		}
 
 		PQclear(res);
+		destroyPQExpBuffer(query);
 		pg_free(nm);
 	}
 }