diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 38af35a1acd..513e1f3b82f 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -517,7 +517,7 @@ class StatefulIncrementalDecoder(codecs.IncrementalDecoder):
     """
 
     def __init__(self, errors='strict'):
-        codecs.IncrementalEncoder.__init__(self, errors)
+        codecs.IncrementalDecoder.__init__(self, errors)
         self.reset()
 
     def __repr__(self):