diff --git a/src/test/test-socket-util.c b/src/test/test-socket-util.c
index 201ce6667de..5b1574e8ea2 100644
--- a/src/test/test-socket-util.c
+++ b/src/test/test-socket-util.c
@@ -487,7 +487,7 @@ static void test_getpeercred_getpeergroups(void) {
         if (r == 0) {
                 static const gid_t gids[] = { 3, 4, 5, 6, 7 };
                 gid_t *test_gids;
-                gid_t *peer_groups = NULL;
+                _cleanup_free_ gid_t *peer_groups = NULL;
                 size_t n_test_gids;
                 uid_t test_uid;
                 gid_t test_gid;