diff --git a/testing/web-platform/meta/requestidlecallback/idlharness.window.js.ini b/testing/web-platform/meta/requestidlecallback/idlharness.window.js.ini
new file mode 100644
index 000000000000..547055c7d27f
--- /dev/null
+++ b/testing/web-platform/meta/requestidlecallback/idlharness.window.js.ini
@@ -0,0 +1,5 @@
+[idlharness.window.html]
+  expected: TIMEOUT
+  [IdleDeadline object setup]
+    expected: TIMEOUT
+