diff --git a/rpyc/lib/colls.py b/rpyc/lib/colls.py
index e3b2be98..5cae9a06 100644
--- a/rpyc/lib/colls.py
+++ b/rpyc/lib/colls.py
@@ -37,6 +37,7 @@ def __getitem__(self, key):
         obj = self._dict[key]()
         if obj is None:
             raise KeyError(key)
+        self[key] = obj
         return obj
 
     def __setitem__(self, key, value):