diff --git a/addons/web/http.py b/addons/web/http.py
index 663acee9ebc..f92a1b8c687 100644
--- a/addons/web/http.py
+++ b/addons/web/http.py
@@ -197,19 +197,14 @@ class JsonRequest(WebRequest):
             error = {
                 'code': 100,
                 'message': "OpenERP Session Invalid",
-                'data': dict(se, **{
-                    'type': 'session_invalid',
-                })
+                'data': se
             }
         except Exception, e:
             se = serialize_exception(e)
             error = {
                 'code': 200,
                 'message': "OpenERP Server Error",
-                'data': dict(se, **{
-                    'type': 'server_exception',
-                    'fault_code': se["message"],
-                })
+                'data': se
             }
         if error:
             response["error"] = error
@@ -296,10 +291,7 @@ class HttpRequest(WebRequest):
             error = {
                 'code': 200,
                 'message': "OpenERP Server Error",
-                'data': dict(se, **{
-                    'type': 'server_exception',
-                    'fault_code': se["message"],
-                })
+                'data': se
             }
             r = werkzeug.exceptions.InternalServerError(cgi.escape(simplejson.dumps(error)))
         if self.debug or 1:
diff --git a/addons/web/static/src/js/corelib.js b/addons/web/static/src/js/corelib.js
index 5bbd5316521..edd23e14522 100644
--- a/addons/web/static/src/js/corelib.js
+++ b/addons/web/static/src/js/corelib.js
@@ -991,7 +991,7 @@ instance.web.JsonRPC = instance.web.Class.extend(instance.web.PropertiesMixin, {
                     self.trigger('response', response);
                 if (!response.error) {
                     deferred.resolve(response["result"], textStatus, jqXHR);
-                } else if (response.error.data.type === "session_invalid") {
+                } else if (response.error.code === 100) {
                     self.uid = false;
                 } else {
                     deferred.reject(response.error, $.Event());