diff -r bf6bc4681383 -r 19ac0d8ee9a2 mercurial/fileset.py
--- a/mercurial/fileset.py	Sun Jul 21 18:45:42 2013 -0500
+++ b/mercurial/fileset.py	Tue Jul 23 14:18:56 2013 -0500
@@ -27,7 +27,7 @@
 
 keywords = set(['and', 'or', 'not'])
 
-globchars = ".*{}[]?/\\"
+globchars = ".*{}[]?/\\_"
 
 def tokenize(program):
     pos, l = 0, len(program)