diff --git a/rma_operating_unit/models/rma_order.py b/rma_operating_unit/models/rma_order.py
index d11f992d..923724d1 100644
--- a/rma_operating_unit/models/rma_order.py
+++ b/rma_operating_unit/models/rma_order.py
@@ -11,7 +11,7 @@ class RmaOrder(models.Model):
     _inherit = "rma.order"
 
     @api.multi
-    @api.constrains('rma_line_ids', 'rma_line_ids.operating_unit')
+    @api.constrains('rma_line_ids', 'rma_line_ids.operating_unit_id')
     def _check_operating_unit(self):
         for rma in self:
             bad_lines = rma.rma_line_ids.filtered(