diff --git a/odoo/addons/base/rng/gantt_view.rng b/odoo/addons/base/rng/gantt_view.rng
index 57eece69d8d..095efcf7b28 100644
--- a/odoo/addons/base/rng/gantt_view.rng
+++ b/odoo/addons/base/rng/gantt_view.rng
@@ -25,6 +25,8 @@
             <rng:optional><rng:attribute name="consolidation"/></rng:optional>
             <rng:optional><rng:attribute name="consolidation_max"/></rng:optional>
             <rng:optional><rng:attribute name="consolidation_exclude"/></rng:optional>
+            <!-- Shouldn't be forward ported to >= saas-12.2 -->
+            <rng:optional><rng:attribute name="duration_unit"/></rng:optional>
             <rng:empty/>
         </rng:element>
     </rng:define>