diff --git a/addons/mail/static/src/model/model_field_relation_set.js b/addons/mail/static/src/model/model_field_relation_set.js
index a69ebd5c828..8f067af3c76 100644
--- a/addons/mail/static/src/model/model_field_relation_set.js
+++ b/addons/mail/static/src/model/model_field_relation_set.js
@@ -77,6 +77,15 @@ export class RelationSet {
                                     }
                                     break;
                                 }
+                                case 'falsy-first': {
+                                    if (!valA) {
+                                        return -1;
+                                    }
+                                    if (!valB) {
+                                        return 1;
+                                    }
+                                    break;
+                                }
                                 case 'case-insensitive-asc': {
                                     if (typeof valA !== 'string' || typeof valB !== 'string') {
                                         break;
diff --git a/addons/mail/static/src/models/follower_subtype.js b/addons/mail/static/src/models/follower_subtype.js
index 7a240514c09..4484012bfd3 100644
--- a/addons/mail/static/src/models/follower_subtype.js
+++ b/addons/mail/static/src/models/follower_subtype.js
@@ -57,6 +57,8 @@ registerModel({
         parentModel: attr(),
         // AKU FIXME: use relation instead
         resModel: attr(),
-        sequence: attr(),
+        sequence: attr({
+            default: 1,
+        }),
     },
 });
diff --git a/addons/mail/static/src/models/follower_subtype_list.js b/addons/mail/static/src/models/follower_subtype_list.js
index 808f047e0ae..f770e81c0e2 100644
--- a/addons/mail/static/src/models/follower_subtype_list.js
+++ b/addons/mail/static/src/models/follower_subtype_list.js
@@ -49,6 +49,12 @@ registerModel({
          */
         _sortFollowerSubtypeViews() {
             return [
+                ['falsy-first', 'subtype.parentModel'],
+                ['case-insensitive-asc', 'subtype.parentModel'],
+                ['falsy-first', 'subtype.resModel'],
+                ['case-insensitive-asc', 'subtype.resModel'],
+                ['smaller-first', 'subtype.isInternal'],
+                ['smaller-first', 'subtype.sequence'],
                 ['smaller-first', 'subtype.id'],
             ];
         },