diff --git a/pygit2/py2.py b/pygit2/py2.py
index 3c57fba..a2d2359 100644
--- a/pygit2/py2.py
+++ b/pygit2/py2.py
@@ -54,4 +54,4 @@ def to_str(s):
     if type(s) is unicode:
         return s.encode()
 
-    raise TypeError, 'unexpected type "%s"' % repr(s)
+    raise TypeError('unexpected type "%s"' % repr(s))