diff -r 7627fea85a6d Lib/lib2to3/pgen2/tokenize.py
--- a/Lib/lib2to3/pgen2/tokenize.py	Fri Sep 06 10:26:48 2013 +0100
+++ b/Lib/lib2to3/pgen2/tokenize.py	Fri Sep 06 18:59:54 2013 +0400
@@ -236,7 +236,7 @@
                 startline = False
             toks_append(tokval)
 
-cookie_re = re.compile("coding[:=]\s*([-\w.]+)")
+cookie_re = re.compile("#[^\r\n]*coding[:=]\s*([-\w.]+)")
 
 def _get_normal_name(orig_enc):
     """Imitates get_normal_name in tokenizer.c."""