diff --git a/content/base/test/test_bug513194.html b/content/base/test/test_bug513194.html
index 0520e74dbacc..eeffd77bee8b 100644
--- a/content/base/test/test_bug513194.html
+++ b/content/base/test/test_bug513194.html
@@ -17,10 +17,15 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=513194
 // The use of document.write is deliberate.  We are testing for the
 // HTML parser to call the CSS parser once and only once when it
 // encounters a new <style> element.
-SimpleTest.runTestExpectingConsoleMessages(
-  function () { document.write("<style>qux { foo : bar; }<\/style>") },
-  [{ errorMessage: /Unknown property/ }]
-);
+function doTest() {
+  SimpleTest.runTestExpectingConsoleMessages(
+    function () { document.write("<style>qux { foo : bar; }<\/style>") },
+    [{ errorMessage: /Unknown property/ }]
+  );
+}
+
+SpecialPowers.pushPrefEnv({'set':[["layout.css.report_errors", true]]},
+                          function() { doTest(); });
 </script>
 </body>
 </html>