diff --git a/addons/web/static/tests/qunit.js b/addons/web/static/tests/qunit.js
index 54a39b5e6c1..bf266554c8d 100644
--- a/addons/web/static/tests/qunit.js
+++ b/addons/web/static/tests/qunit.js
@@ -309,6 +309,7 @@
     });
 
     QUnit.debug = (name, cb) => {
+        document.body.classList.add("debug");
         QUnit.config.debug = true;
         QUnit.only(name, cb);
     };