diff --git a/LayoutTests/ChangeLog b/LayoutTests/ChangeLog
index 4850cc8..9ae09e1 100644
--- a/LayoutTests/ChangeLog
+++ b/LayoutTests/ChangeLog
@@ -1,5 +1,18 @@
 2019-10-18  Daniel Bates  <dabates@apple.com>
 
+        Layout Test http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html is flaky
+        https://bugs.webkit.org/show_bug.cgi?id=202481
+        <rdar://problem/55916200>
+
+        Reviewed by Youenn Fablet.
+
+        Have the iframe's document call testRunner.notifyDone() instead of assuming that the document will
+        be loaded by the next turn of the event loop.
+
+        * http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html:
+
+2019-10-18  Daniel Bates  <dabates@apple.com>
+
         REGRESSION (r241747): [iOS] Adjust default SVG focus ring width to match width for HTML documents
         https://bugs.webkit.org/show_bug.cgi?id=203011
 
diff --git a/LayoutTests/http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html b/LayoutTests/http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html
index 9cf9ee8..77cea21 100644
--- a/LayoutTests/http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html
+++ b/LayoutTests/http/tests/security/contentSecurityPolicy/iframe-allowed-when-loaded-via-javascript-url.html
@@ -12,7 +12,7 @@
 </head>
 <body>
 <script>
-var test = "javascript:'<iframe src=http://localhost:8000/security/contentSecurityPolicy/resources/alert-pass.html></iframe><script>window.testRunner && window.setTimeout(() => testRunner.notifyDone(), 0);</" + "script>'";
+var test = "javascript:'<iframe src=http://localhost:8000/security/contentSecurityPolicy/resources/alert-pass.html?notifyDone=1></iframe>'";
 window.open(test, "_self");
 </script>
 </body>