fix test that wasn't working as expected #4990
diff --git a/Lib/test/test_codeccallbacks.py b/Lib/test/test_codeccallbacks.py
index 656551d..db0bc96 100644
--- a/Lib/test/test_codeccallbacks.py
+++ b/Lib/test/test_codeccallbacks.py
@@ -579,7 +579,7 @@
         encs = ("ascii", "latin-1", "iso-8859-1", "iso-8859-15")
 
         for res in results:
-            codecs.register_error("test.badhandler", lambda: res)
+            codecs.register_error("test.badhandler", lambda x: res)
             for enc in encs:
                 self.assertRaises(
                     TypeError,