--- a/gin_toolbar.module
+++ b/gin_toolbar.module
@@ -621,6 +621,10 @@
       else {
         $gin_activated = array_key_exists('gin', $frontend_base_themes);
       }
+
+      // Allow other modules to override the computed activation state, e.g.
+      // to exempt specific users from the Gin toolbar.
+      \Drupal::moduleHandler()->alter('gin_toolbar_is_active', $gin_activated);
     }
   }
   return $gin_activated;