diff --git a/user/test/com/google/gwt/http/client/RequestBuilderTest.java b/user/test/com/google/gwt/http/client/RequestBuilderTest.java
index a0aa582..4e01700 100644
--- a/user/test/com/google/gwt/http/client/RequestBuilderTest.java
+++ b/user/test/com/google/gwt/http/client/RequestBuilderTest.java
@@ -45,6 +45,25 @@
     return ua.indexOf("webkit") != -1; 
   }-*/;
 
+  /**
+   * HACK: Part of a work around for FF 3.5's failure to throw an exception when
+   * an XmlHttpRequest that violates the same origin policy is made.
+   */
+  private static native boolean isFirefox35() /*-{
+    var ua = navigator.userAgent.toLowerCase();
+    if (ua.indexOf("gecko") == -1) {
+      return false;
+    }
+    var result = /firefox\/([0-9]+\.[0-9]+)/.exec(ua.toLowerCase());
+    if (result && result.length == 2) {
+      var version = parseFloat(result[1]);
+      if (version >= 3.5) {
+        return true;
+      }
+    }
+    return false;
+  }-*/;
+
   @Override
   public String getModuleName() {
     return "com.google.gwt.http.RequestBuilderTest";
@@ -109,13 +128,17 @@
         }
       });
 
-      if (isSafari()) {
+      if (isSafari() || isFirefox35()) {
         /*
          * HACK: Safari 2.0.4 will not throw an exception for XHR's that violate
          * the same-origin policy. It appears to silently ignore them so we do
          * not fail this test if we are on Safari and the
          * RequestPermissionException is not thrown. Even though Safari 3.0.4
          * does throw an exception in this case, we exclude it anyway.
+         * 
+         * FF3.5 allows XHR's to violate the same-origin policy and offers no
+         * way to disable the feature from the client. Only the server can block
+         * the same origin policy.
          */
       } else {
         /*