diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 49f0ee886af..f36065f4a3c 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -3491,6 +3491,7 @@ append_depends_on_extension(Archive *fout,
 		}
 
 		PQclear(res);
+		destroyPQExpBuffer(query);
 		pg_free(nm);
 	}
 }