diff --git a/app/src/Controller/Group/GroupApi.php b/app/src/Controller/Group/GroupApi.php
index 61341b6..d4655dc 100644
--- a/app/src/Controller/Group/GroupApi.php
+++ b/app/src/Controller/Group/GroupApi.php
@@ -46,12 +46,29 @@ public function __construct(
     public function __invoke(GroupInterface $group, Response $response): Response
     {
         $this->validateAccess($group);
+        $group = $this->mutateGroup($group);
         $payload = json_encode($group, JSON_THROW_ON_ERROR);
         $response->getBody()->write($payload);
 
         return $response->withHeader('Content-Type', 'application/json');
     }
 
+    /**
+     * Add or remove fields from the group object before returning it.
+     * TIP : When extending this class, you can use this method to add your own fields.
+     *
+     * @param GroupInterface $group
+     *
+     * @return GroupInterface
+     */
+    protected function mutateGroup(GroupInterface $group): GroupInterface
+    {
+        // Add the user count to the group object
+        $group->loadCount('users');
+
+        return $group;
+    }
+
     /**
      * Validate access to the page.
      *
diff --git a/app/tests/Controller/Group/GroupApiTest.php b/app/tests/Controller/Group/GroupApiTest.php
index 20778aa..88f5baa 100644
--- a/app/tests/Controller/Group/GroupApiTest.php
+++ b/app/tests/Controller/Group/GroupApiTest.php
@@ -99,7 +99,8 @@ public function testApi(): void
             'description',
             'icon',
             'created_at',
-            'updated_at'
+            'updated_at',
+            'users_count',
         ], $response);
     }
 }