diff --git a/hgext/chgserver.py b/hgext/chgserver.py
--- a/hgext/chgserver.py
+++ b/hgext/chgserver.py
@@ -314,7 +314,7 @@ class channeledsystem(object):
         self.channel = channel
 
     def __call__(self, cmd, environ, cwd):
-        args = [util.quotecommand(cmd), cwd or '.']
+        args = [util.quotecommand(cmd), os.path.abspath(cwd or '.')]
         args.extend('%s=%s' % (k, v) for k, v in environ.iteritems())
         data = '\0'.join(args)
         self.out.write(struct.pack('>cI', self.channel, len(data)))