diff --git a/testing/web-platform/tests/interfaces/hr-time.idl b/testing/web-platform/tests/interfaces/hr-time.idl
index 33d602cf971c..0e30c3f150f9 100644
--- a/testing/web-platform/tests/interfaces/hr-time.idl
+++ b/testing/web-platform/tests/interfaces/hr-time.idl
@@ -13,6 +13,5 @@ interface Performance : EventTarget {
 };
 
 partial interface mixin WindowOrWorkerGlobalScope {
-    [Replaceable]
-    readonly    attribute Performance performance;
+  [Replaceable] readonly attribute Performance performance;
 };