diff --git a/builtin/repack.c b/builtin/repack.c
index 62cfa50c50..2b9bf0318a 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -425,9 +425,11 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 
 		free(promisor_name);
 	}
+
 	fclose(out);
 	if (finish_command(&cmd))
 		die(_("could not finish pack-objects to repack promisor objects"));
+	strbuf_release(&line);
 }
 
 struct pack_geometry {