diff --git a/openerp/workflow/wkf_expr.py b/openerp/workflow/wkf_expr.py
index 16b186c904d..b4d6c5b9ccc 100644
--- a/openerp/workflow/wkf_expr.py
+++ b/openerp/workflow/wkf_expr.py
@@ -44,8 +44,10 @@ class Env(dict):
 def _eval_expr(cr, ident, workitem, action):
     ret=False
     assert action, 'You used a NULL action in a workflow, use dummy node instead.'
-    for line in filter(None, action.split('\n')):
+    for line in action.split('\n'):
         line = line.strip()
+        if not line:
+            continue
         uid=ident[0]
         model=ident[1]
         ids=[ident[2]]