diff --git a/app/assets/javascripts/discourse/tests/test-boot-ember-cli.js b/app/assets/javascripts/discourse/tests/test-boot-ember-cli.js
index eabbec1ef7c..66bf28a39e0 100644
--- a/app/assets/javascripts/discourse/tests/test-boot-ember-cli.js
+++ b/app/assets/javascripts/discourse/tests/test-boot-ember-cli.js
@@ -61,6 +61,7 @@ document.addEventListener("discourse-booted", () => {
     loadTests: false,
     startTests: !disableAutoStart,
     setupEmberOnerrorValidation: !skipCore,
+    setupTestIsolationValidation: true,
   });
 });