diff --git a/Lib/calendar.py b/Lib/calendar.py
index 321059d0552..c2a9775ebfe 100644
--- a/Lib/calendar.py
+++ b/Lib/calendar.py
@@ -50,7 +50,7 @@ def __getitem__(self, i):
                      for j in range(7)]
         return data[i]
 
-    def __len__(self_):
+    def __len__(self):
         return 7
 
 # Full and abbreviated names of weekdays