diff --git a/solutions/object_oriented_design/lru_cache/lru_cache.ipynb b/solutions/object_oriented_design/lru_cache/lru_cache.ipynb
index e78966d1..a31907b8 100644
--- a/solutions/object_oriented_design/lru_cache/lru_cache.ipynb
+++ b/solutions/object_oriented_design/lru_cache/lru_cache.ipynb
@@ -56,7 +56,8 @@
     "\n",
     "    def __init__(self, results):\n",
     "        self.results = results\n",
-    "        self.next = next\n",
+    "        self.prev = None\n",
+    "        self.next = None\n",
     "\n",
     "\n",
     "class LinkedList(object):\n",