diff --git a/src/fix.py b/src/fix.py
index b348ae05e..9207b0c2e 100644
--- a/src/fix.py
+++ b/src/fix.py
@@ -220,7 +220,7 @@ class queue(dict):
             
 class MaxLengthQueue(queue):
     __slots__ = ('length',)
-    def __init__(length, *args):
+    def __init__(self, length, *args):
         self.length = length
         queue.__init__(self, *args)