diff --git a/openerp/addons/base/ir/ir_ui_view.py b/openerp/addons/base/ir/ir_ui_view.py
index 996053bd35c..767d71b76b0 100644
--- a/openerp/addons/base/ir/ir_ui_view.py
+++ b/openerp/addons/base/ir/ir_ui_view.py
@@ -125,7 +125,7 @@ class view(osv.osv):
 
     def graph_get(self, cr, uid, id, model, node_obj, conn_obj, src_node, des_node, label, scale, context=None):
         if not label:
-            label = []
+            label = '[]'
         nodes=[]
         nodes_name=[]
         transitions=[]