diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index c4a3e2c1a6..dd2e58e0b6 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4329,6 +4329,7 @@ append_depends_on_extension(Archive *fout,
 		}
 
 		PQclear(res);
+		destroyPQExpBuffer(query);
 		pg_free(nm);
 	}
 }