diff --git a/mrp_operations_extension/models/mrp_bom.py b/mrp_operations_extension/models/mrp_bom.py
index 4504e9435..3bbf11508 100644
--- a/mrp_operations_extension/models/mrp_bom.py
+++ b/mrp_operations_extension/models/mrp_bom.py
@@ -43,7 +43,7 @@ class MrpBom(models.Model):
             seq = work_order['sequence'] - level
             routing_lines = routing_line_obj.search([
                 ('routing_id', '=', routing_id), ('sequence', '=', seq)])
-            routing_line_id = routing_lines.id
+            routing_line_id = routing_lines and routing_lines[0].id or False
             for routing_line in routing_lines:
                 if routing_line.name in work_order['name']:
                     routing_line_id = routing_line.id
diff --git a/mrp_operations_extension/models/mrp_routing.py b/mrp_operations_extension/models/mrp_routing.py
index 474ac7d02..56c87ee94 100644
--- a/mrp_operations_extension/models/mrp_routing.py
+++ b/mrp_operations_extension/models/mrp_routing.py
@@ -84,8 +84,9 @@ class MrpRoutingWorkcenter(models.Model):
                     'op_number': self.operation.op_number,
                 }
                 op_wc_lst.append(data)
-            op_wc_lst[0]['default'] = True
-            self.op_wc_lines = op_wc_lst
+            if op_wc_lst:
+                op_wc_lst[0]['default'] = True
+                self.op_wc_lines = op_wc_lst
 
     @api.one
     @api.onchange('op_wc_lines')