diff --git a/fusion_plating/fusion_plating_configurator/models/sale_order_line.py b/fusion_plating/fusion_plating_configurator/models/sale_order_line.py
index abf7b309..98b6616a 100644
--- a/fusion_plating/fusion_plating_configurator/models/sale_order_line.py
+++ b/fusion_plating/fusion_plating_configurator/models/sale_order_line.py
@@ -18,6 +18,7 @@ class SaleOrderLine(models.Model):
     # Nullable during Phase A; flipped to required in Phase C.
     x_fc_internal_description = fields.Text(
         string='Internal Description',
+        required=True,
         help='Shop-floor instructions. Prints on WO / traveler. Never on customer docs.',
     )
     x_fc_description_template_id = fields.Many2one(