diff --git a/hgext/win32mbcs.py b/hgext/win32mbcs.py
--- a/hgext/win32mbcs.py
+++ b/hgext/win32mbcs.py
@@ -127,7 +127,9 @@ def wrapname(name, wrapper):
 # NOTE: os.path.dirname() and os.path.basename() are safe because
 #       they use result of os.path.split()
 funcs = '''os.path.join os.path.split os.path.splitext
- os.path.splitunc os.path.normpath os.path.normcase os.makedirs
+ os.path.splitunc os.path.normpath os.makedirs
+ mercurial.windows.normcase
+ mercurial.util.normcase
  mercurial.util.endswithsep mercurial.util.splitpath mercurial.util.checkcase
  mercurial.util.fspath mercurial.util.pconvert mercurial.util.normpath
  mercurial.util.checkwinfilename mercurial.util.checkosfilename'''
diff --git a/mercurial/windows.py b/mercurial/windows.py
--- a/mercurial/windows.py
+++ b/mercurial/windows.py
@@ -131,7 +131,8 @@ def localpath(path):
 def normpath(path):
     return pconvert(os.path.normpath(path))
 
-normcase = os.path.normcase
+def normcase(path):
+    return path.upper()
 
 def realpath(path):
     '''