diff --git a/Python/getargs.c b/Python/getargs.c
index 17d5993..e1cef0c 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -551,7 +551,7 @@
 
 
 #define UNICODE_DEFAULT_ENCODING(arg) \
-    _PyUnicode_AsDefaultEncodedString(arg, NULL)
+    _PyUnicode_AsDefaultEncodedString(arg)
 
 /* Format an error message generated by convertsimple(). */