1 files changed, 3 insertions, 1 deletions
diff --git a/src/core/unit.c b/src/core/unit.c
index d8ab5781b0..dc8325515c 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -2400,9 +2400,11 @@ int unit_set_slice(Unit *u, Unit *slice) {
         if (UNIT_DEREF(u->slice) == slice)
                 return 0;
 
-        if (UNIT_ISSET(u->slice))
+        /* Disallow slice changes if @u is already bound to cgroups */
+        if (UNIT_ISSET(u->slice) && u->cgroup_realized)
                 return -EBUSY;
 
+        unit_ref_unset(&u->slice);
         unit_ref_set(&u->slice, slice);
         return 1;
 }