diff --git a/addons/project/views/project_views.xml b/addons/project/views/project_views.xml
index 5994c352452..3af288906b3 100644
--- a/addons/project/views/project_views.xml
+++ b/addons/project/views/project_views.xml
@@ -1711,7 +1711,7 @@
             <field name="mode">primary</field>
             <field name="arch" type="xml">
                 <tree position="attributes">
-                    <attribute name="default_group_by">project_id</attribute>
+                    <attribute name="default_group_by"/>
                 </tree>
                 <field name="project_id" position="attributes">
                     <attribute name="invisible">0</attribute>