diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/relevant-mutations.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/relevant-mutations.html.ini
index 9718d9d25a51..1d7828ea6ffe 100644
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/relevant-mutations.html.ini
+++ b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/relevant-mutations.html.ini
@@ -1,49 +1,50 @@
 [relevant-mutations.html]
   type: testharness
+  expected: TIMEOUT
   [src removed]
-    expected: FAIL
+    expected: TIMEOUT
 
   [srcset removed]
-    expected: FAIL
+    expected: TIMEOUT
 
   [sizes set]
-    expected: FAIL
+    expected: TIMEOUT
 
   [sizes changed]
-    expected: FAIL
+    expected: TIMEOUT
 
   [sizes removed]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin absent to empty]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin absent to anonymous]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin absent to use-credentials]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin empty to absent]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin empty to use-credentials]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin anonymous to absent]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin anonymous to use-credentials]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin use-credentials to absent]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin use-credentials to empty]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin use-credentials to anonymous]
-    expected: FAIL
+    expected: TIMEOUT
 
   [crossorigin state not changed: empty to anonymous]
     expected: FAIL
diff --git a/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html b/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
index 535bada1f234..2b543812c08c 100644
--- a/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
+++ b/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
@@ -107,10 +107,9 @@ function t(desc, func, expect) {
     var img = document.querySelector('[data-desc="' + desc + '"]');
     img.onload = img.onerror = this.unreached_func('update the image data was run');
     if (expect == 'timeout') {
-      setTimeout(this.step_func_done(), 250);
+      setTimeout(this.step_func_done(), 1000);
     } else {
       img['on' + expect] = this.step_func_done(function() {});
-      setTimeout(this.unreached_func('update the image data was not run'), 250)
     }
     func.call(this, img);
   }, desc);