diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
index f494617ffa..20346c7f15 100644
--- a/src/basic/cgroup-util.h
+++ b/src/basic/cgroup-util.h
@@ -216,7 +216,7 @@ static inline int cg_pidref_get_unit(const PidRef *pidref, char **ret_unit) {
 }
 int cg_pid_get_user_unit_full(pid_t pid, char **ret_unit, char **ret_subgroup);
 static inline int cg_pid_get_user_unit(pid_t pid, char **ret_unit) {
-        return cg_pid_get_unit_full(pid, ret_unit, NULL);
+        return cg_pid_get_user_unit_full(pid, ret_unit, NULL);
 }
 int cg_pidref_get_user_unit_full(const PidRef *pidref, char **ret_unit, char **ret_subgroup);
 static inline int cg_pidref_get_user_unit(const PidRef *pidref, char **ret_unit) {
diff --git a/src/libsystemd/sd-login/test-login.c b/src/libsystemd/sd-login/test-login.c
index 7c2b68a5c7..2f15b029b0 100644
--- a/src/libsystemd/sd-login/test-login.c
+++ b/src/libsystemd/sd-login/test-login.c
@@ -59,6 +59,9 @@ TEST(login) {
         log_info("sd_pid_get_user_unit(0, …) → %s / \"%s\"", e(r), strnull(user_unit));
         assert_se(IN_SET(r, 0, -ENODATA));
 
+        /* Coverage for https://github.com/systemd/systemd/issues/39949 */
+        assert_se(!unit || !user_unit || !streq(unit, user_unit));
+
         r = sd_pid_get_slice(0, &slice);
         log_info("sd_pid_get_slice(0, …) → %s / \"%s\"", e(r), strnull(slice));
         assert_se(IN_SET(r, 0, -ENODATA));