diff --git a/addons/repair/views/repair_views.xml b/addons/repair/views/repair_views.xml
index 6beb3113f7a..8a0cefd018b 100644
--- a/addons/repair/views/repair_views.xml
+++ b/addons/repair/views/repair_views.xml
@@ -67,7 +67,7 @@
                             <field name="product_uom_category_id" invisible="1"/>
                             <label for="product_qty"/>
                             <div class="o_row">
-                                <field name="product_qty"/>
+                                <field name="product_qty" attrs="{'readonly':[('tracking', 'in', ['serial'])]}"/>
                                 <field name="product_uom" groups="uom.group_uom"/>
                             </div>
                             <field name="lot_id" context="{'default_product_id': product_id, 'default_company_id': company_id}" groups="stock.group_production_lot" attrs="{'required':[('tracking', 'in', ['serial', 'lot'])], 'invisible': [('tracking', 'not in', ['serial', 'lot'])], 'readonly': [('state', '=', 'done')]}"/>