diff --git a/line.py b/line.py
index 3949a8b..5569506 100644
--- a/line.py
+++ b/line.py
@@ -28,17 +28,23 @@ except :
     image_limit = 2000
 
 
+STATES2 = {}
+STATES2.update(STATES)
+DEPENDS2 = []
+DEPENDS2.extend(DEPENDS)
+
+
 class Line(metaclass=PoolMeta):
     __name__ = 'cashbook.line'
 
     media = fields.Binary(string='Image of PDF', filename='media_name',
         file_id='media_id', store_prefix=store_prefix,
-        states=STATES, depends=DEPENDS)
+        states=STATES2, depends=DEPENDS2)
     media_name = fields.Char(string='File name',
         states={
             'required': Bool(Eval('media')),
-            'readonly': STATES['readonly'],
-        }, depends=DEPENDS)
+            'readonly': STATES2['readonly'],
+        }, depends=DEPENDS2)
     media_id = fields.Char(string='File ID', readonly=True)
     media_mime = fields.Char(string='MIME', readonly=True)
     media_size = fields.Integer(string='File size', readonly=True)