diff --git a/Lib/pickle.py b/Lib/pickle.py
index 33a1e77..f833d86 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -288,7 +288,7 @@
                 write(POP_MARK + self.get(memo[d][0]))
                 return
            
-            write(POP * (len(object) + 1) + self.get(mem[d][0]))
+            write(POP * (len(object) + 1) + self.get(memo[d][0]))
             return
 
         memo_len = len(memo)