diff --git a/bin/osv/fields.py b/bin/osv/fields.py
index c3a3c38826e..b87e9ab6483 100644
--- a/bin/osv/fields.py
+++ b/bin/osv/fields.py
@@ -64,6 +64,8 @@ class _column(object):
     _symbol_get = None
 
     def __init__(self, string='unknown', required=False, readonly=False, domain=None, context={}, states=None, priority=0, change_default=False, size=None, ondelete="set null", translate=False, select=False, **args):
+        if not context:
+            context = {}
         self.states = states or {}
         self.string = string
         self.readonly = readonly