diff --git a/diff2HtmlCompare.py b/diff2HtmlCompare.py
index 644ce93..e730bb4 100644
--- a/diff2HtmlCompare.py
+++ b/diff2HtmlCompare.py
@@ -145,7 +145,7 @@ def __init__(self, isLeft, diffs, *args, **kwargs):
         self.diffs = diffs
         super(DiffHtmlFormatter, self).__init__(*args, **kwargs)
 
-    def wrap(self, source, outfile):
+    def wrap(self, source, outfile=None):
         return self._wrap_code(source)
 
     def getDiffLineNos(self):