diff --git a/ct/modules/task-queue-sk/task-queue-sk_test.js b/ct/modules/task-queue-sk/task-queue-sk_test.js
index ece9016..02c5a8e 100644
--- a/ct/modules/task-queue-sk/task-queue-sk_test.js
+++ b/ct/modules/task-queue-sk/task-queue-sk_test.js
@@ -75,9 +75,9 @@
   it('task details works', async () => {
     const table = await loadTableWithReplies([resultSetOneItem]);
 
-    expect($$('.dialog-background', table)).to.have.class('hidden');
+    expect($$('.dialog-background', table).className).to.contain('hidden');
     $$('.details', table).click();
 
-    expect($$('.dialog-background', table)).to.not.have.class('hidden');
+    expect($$('.dialog-background', table).className).to.not.contain('hidden');
   });
 });