diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index da37b52dbe..dff6543bf5 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -388,7 +388,7 @@ int cg_kill_recursive(
         while ((r = cg_read_subgroup(d, &fn)) > 0) {
                 _cleanup_free_ char *p = NULL;
 
-                p = path_join(path, fn);
+                p = path_join(empty_to_root(path), fn);
                 free(fn);
                 if (!p)
                         return -ENOMEM;
@@ -522,7 +522,7 @@ int cg_migrate_recursive(
         while ((r = cg_read_subgroup(d, &fn)) > 0) {
                 _cleanup_free_ char *p = NULL;
 
-                p = path_join(pfrom, fn);
+                p = path_join(empty_to_root(pfrom), fn);
                 free(fn);
                 if (!p)
                         return -ENOMEM;
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 0428f62481..9a1aec144e 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -2490,7 +2490,7 @@ static int unit_watch_pids_in_path(Unit *u, const char *path) {
                 while ((r = cg_read_subgroup(d, &fn)) > 0) {
                         _cleanup_free_ char *p = NULL;
 
-                        p = path_join(path, fn);
+                        p = path_join(empty_to_root(path), fn);
                         free(fn);
 
                         if (!p)