diff --git a/content/base/test/Makefile.in b/content/base/test/Makefile.in
index c75157594fc4..f2e579cdce8c 100644
--- a/content/base/test/Makefile.in
+++ b/content/base/test/Makefile.in
@@ -453,6 +453,7 @@ _TEST_FILES2 = \
 		test_treewalker_nextsibling.xml \
 		test_bug614058.html \
 		test_bug590771.html \
+		test_bug622117.html \
 		$(NULL)
 
 # This test fails on the Mac for some reason
diff --git a/content/base/test/test_bug622117.html b/content/base/test/test_bug622117.html
new file mode 100644
index 000000000000..ef2601195fd1
--- /dev/null
+++ b/content/base/test/test_bug622117.html
@@ -0,0 +1,44 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=622117
+-->
+<head>
+  <title>Test for Bug 622117</title>
+  <script type="application/javascript" src="/MochiKit/packed.js"></script>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=622117">Mozilla Bug 622117</a>
+<p id="display">
+  <iframe id="testframe"
+          src="data:text/html,<a href='data:text/plain,PASS' onclick='throw 1'>Click me</a>">
+  </iframe>
+</p>
+<div id="content" style="display: none">
+  
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Bug 622117 **/
+SimpleTest.waitForExplicitFinish();
+
+const PASSURL = "data:text/plain,PASS";
+
+SimpleTest.waitForFocus(function() {
+  $("testframe").onload = function() {
+    is(this.contentDocument.documentElement.textContent, "PASS", "Should have loaded link");
+    SimpleTest.finish();
+  };
+
+  var win = $("testframe").contentWindow;
+  var a = win.document.getElementsByTagName("a")[0];
+  synthesizeMouseAtCenter(a, {}, win);
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/widget/public/nsGUIEvent.h b/widget/public/nsGUIEvent.h
index 8a3e73c68d5f..fe245c0218b4 100644
--- a/widget/public/nsGUIEvent.h
+++ b/widget/public/nsGUIEvent.h
@@ -158,7 +158,7 @@ class nsHashKey;
 
 #define NS_EVENT_FLAG_EXCEPTION_THROWN    0x10000
 
-#define NS_EVENT_FLAG_PREVENT_ANCHOR_ACTIONS 0x10000
+#define NS_EVENT_FLAG_PREVENT_ANCHOR_ACTIONS 0x20000
 
 #define NS_EVENT_CAPTURE_MASK             (~(NS_EVENT_FLAG_BUBBLE | NS_EVENT_FLAG_NO_CONTENT_DISPATCH))
 #define NS_EVENT_BUBBLE_MASK              (~(NS_EVENT_FLAG_CAPTURE | NS_EVENT_FLAG_NO_CONTENT_DISPATCH))
