diff -r f4386cb3252e -r 23c4589fc678 mercurial/fileset.py
--- a/mercurial/fileset.py	Thu Aug 06 22:54:28 2015 -0700
+++ b/mercurial/fileset.py	Sat Aug 08 14:42:27 2015 +0800
@@ -287,7 +287,7 @@
 
 def _sizetomax(s):
     try:
-        s = s.strip()
+        s = s.strip().lower()
         for k, v in util._sizeunits:
             if s.endswith(k):
                 # max(4k) = 5k - 1, max(4.5k) = 4.6k - 1