diff -r b9e1abe1bdfe -r 120db445c179 web/_exceptions.py
--- a/web/_exceptions.py	Fri Apr 23 17:56:01 2010 +0200
+++ b/web/_exceptions.py	Mon Apr 26 16:31:46 2010 +0200
@@ -53,11 +53,8 @@
         self.reason = reason
 
     def dumps(self):
-        try:
-            from json import dumps
-        except ImportError:
-            from simplejson import dumps
-        return dumps({'reason': self.reason})
+        from cubicweb.web import json
+        return json.dumps({'reason': self.reason})
 
 class LogOut(PublishException):
     """raised to ask for deauthentication of a logged in user"""