diff --git a/urogue/pack.c b/urogue/pack.c
index d865584..0c917c4 100644
--- a/urogue/pack.c
+++ b/urogue/pack.c
@@ -54,6 +54,7 @@ swap_top(struct linked_list *top, struct linked_list *node)
     detach(lvl_obj, top);   /* Remove item from level */
 
     obn->next_obj = obt->next_obj;
+    obt->next_obj = NULL;
 
     if (obn->next_obj)
         obn->next_obj->l_prev = NULL;