--- a/caps/tests/mochitest/test_bug292789.html
+++ b/caps/tests/mochitest/test_bug292789.html
@@ -95,13 +95,17 @@ function loadImage(uri, expect, callback
     img.onload = success;
     img.expected = expect;
     img.callback = callback;
     img.src = uri;
     // document.getElementById("content").appendChild(img);
 }
 
 // Start off the script src test, and have it start the img tests when complete.
-testScriptSrc(runImgTest);
+SpecialPowers.pushPrefEnv({
+  set: [
+    ["security.all_resource_uri_content_accessible", true]
+  ]
+}, () => testScriptSrc(runImgTest));
 </script>
 </pre>
 </body>
 </html>