diff --git a/bin/osv/fields.py b/bin/osv/fields.py
index e1f98532527..802d6ccb5a4 100644
--- a/bin/osv/fields.py
+++ b/bin/osv/fields.py
@@ -515,6 +515,9 @@ class many2many(_column):
             return
         obj = obj.pool.get(self._obj)
         for act in values:
+	    if not isinstance(act,tuple):
+		print("incorrect values passed in many2many.set:",values)
+		return
             if act[0] == 0:
                 idnew = obj.create(cr, user, act[2])
                 cr.execute('insert into '+self._rel+' ('+self._id1+','+self._id2+') values (%s,%s)', (id, idnew))