diff --git a/dom/interfaces/threads/nsIDOMWorkers.idl b/dom/interfaces/threads/nsIDOMWorkers.idl
index d6c743d85372..4b636808d37e 100644
--- a/dom/interfaces/threads/nsIDOMWorkers.idl
+++ b/dom/interfaces/threads/nsIDOMWorkers.idl
@@ -83,6 +83,21 @@ interface nsIWorkerErrorEvent : nsIDOMEvent
                       in unsigned long aLinenoArg);
 };
 
+[scriptable, uuid(17a005c3-4f2f-4bb6-b169-c181fa6873de)]
+interface nsIWorkerLocation : nsISupports
+{
+  readonly attribute AUTF8String href;
+  readonly attribute AUTF8String protocol;
+  readonly attribute AUTF8String host;
+  readonly attribute AUTF8String hostname;
+  readonly attribute AUTF8String port;
+  readonly attribute AUTF8String pathname;
+  readonly attribute AUTF8String search;
+  readonly attribute AUTF8String hash;
+
+  AUTF8String toString();
+};
+
 [scriptable, uuid(74fb665a-e477-4ce2-b3c6-c58b1b28b6c3)]
 interface nsIWorkerNavigator : nsISupports
 {
@@ -92,11 +107,12 @@ interface nsIWorkerNavigator : nsISupports
   readonly attribute DOMString userAgent;
 };
 
-[scriptable, uuid(d7d7cf59-6c8a-4598-8753-630953ae7409)]
+[scriptable, uuid(c111e7d3-8044-4458-aa7b-637696ffb841)]
 interface nsIWorkerGlobalScope : nsISupports
 {
   readonly attribute nsIWorkerGlobalScope self;
   readonly attribute nsIWorkerNavigator navigator;
+  readonly attribute nsIWorkerLocation location;
 
   attribute nsIDOMEventListener onerror;
 };
diff --git a/dom/src/threads/Makefile.in b/dom/src/threads/Makefile.in
index aa620c58f344..06e18d4a5ee1 100644
--- a/dom/src/threads/Makefile.in
+++ b/dom/src/threads/Makefile.in
@@ -71,6 +71,7 @@ CPPSRCS = \
   nsDOMThreadService.cpp \
   nsDOMWorker.cpp \
   nsDOMWorkerEvents.cpp \
+  nsDOMWorkerLocation.cpp \
   nsDOMWorkerMessageHandler.cpp \
   nsDOMWorkerNavigator.cpp \
   nsDOMWorkerPool.cpp \
diff --git a/dom/src/threads/nsDOMWorker.cpp b/dom/src/threads/nsDOMWorker.cpp
index 4c919c206ab6..b05338b02b40 100644
--- a/dom/src/threads/nsDOMWorker.cpp
+++ b/dom/src/threads/nsDOMWorker.cpp
@@ -58,6 +58,7 @@
 
 #include "nsDOMThreadService.h"
 #include "nsDOMWorkerEvents.h"
+#include "nsDOMWorkerLocation.h"
 #include "nsDOMWorkerNavigator.h"
 #include "nsDOMWorkerPool.h"
 #include "nsDOMWorkerScriptLoader.h"
@@ -698,6 +699,18 @@ nsDOMWorkerScope::GetNavigator(nsIWorkerNavigator** _retval)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDOMWorkerScope::GetLocation(nsIWorkerLocation** _retval)
+{
+  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+
+  nsCOMPtr<nsIWorkerLocation> location = mWorker->GetLocation();
+  NS_ASSERTION(location, "This should never be null!");
+
+  location.forget(_retval);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDOMWorkerScope::GetOnerror(nsIDOMEventListener** aOnerror)
 {
@@ -1744,6 +1757,24 @@ nsDOMWorker::ResumeFeatures()
   }
 }
 
+nsresult
+nsDOMWorker::SetURI(nsIURI* aURI)
+{
+  NS_ASSERTION(aURI, "Don't hand me a null pointer!");
+  NS_ASSERTION(!mURI && !mLocation, "Called more than once?!");
+  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+
+  mURI = aURI;
+
+  nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
+  NS_ENSURE_TRUE(url, NS_ERROR_NO_INTERFACE);
+
+  mLocation = nsDOMWorkerLocation::NewLocation(url);
+  NS_ENSURE_TRUE(mLocation, NS_ERROR_FAILURE);
+
+  return NS_OK;
+}
+
 nsresult
 nsDOMWorker::FireCloseRunnable(PRIntervalTime aTimeoutInterval,
                                PRBool aClearQueue,
diff --git a/dom/src/threads/nsDOMWorker.h b/dom/src/threads/nsDOMWorker.h
index 56942e4e499c..9b648ef47d4e 100644
--- a/dom/src/threads/nsDOMWorker.h
+++ b/dom/src/threads/nsDOMWorker.h
@@ -266,9 +266,7 @@ private:
     return mURI;
   }
 
-  void SetURI(nsIURI* aURI) {
-    mURI = aURI;
-  }
+  nsresult SetURI(nsIURI* aURI);
 
   nsresult FireCloseRunnable(PRIntervalTime aTimeoutInterval,
                              PRBool aClearQueue,
@@ -277,6 +275,10 @@ private:
 
   nsresult TerminateInternal(PRBool aFromFinalize);
 
+  nsIWorkerLocation* GetLocation() {
+    return mLocation;
+  }
+
 private:
 
   // mParent will live as long as mParentWN but only mParentWN will keep the JS
@@ -314,6 +316,8 @@ private:
 
   nsCOMPtr<nsITimer> mKillTimer;
 
+  nsCOMPtr<nsIWorkerLocation> mLocation;
+
   PRPackedBool mSuspended;
   PRPackedBool mCompileAttempted;
 };
diff --git a/dom/src/threads/nsDOMWorkerLocation.cpp b/dom/src/threads/nsDOMWorkerLocation.cpp
new file mode 100644
index 000000000000..776ab9176c39
--- /dev/null
+++ b/dom/src/threads/nsDOMWorkerLocation.cpp
@@ -0,0 +1,223 @@
+/* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is worker threads.
+ *
+ * The Initial Developer of the Original Code is
+ *   Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2009
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Ben Turner <bent.mozilla@gmail.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsDOMWorkerLocation.h"
+
+#include "nsIClassInfoImpl.h"
+#include "nsITextToSubURI.h"
+#include "nsIURL.h"
+
+#include "nsDOMWorkerMacros.h"
+
+#include "nsAutoPtr.h"
+#include "nsEscape.h"
+#include "nsNetUtil.h"
+
+#define XPC_MAP_CLASSNAME nsDOMWorkerLocation
+#define XPC_MAP_QUOTED_CLASSNAME "WorkerLocation"
+
+#define XPC_MAP_FLAGS                                      \
+  nsIXPCScriptable::USE_JSSTUB_FOR_ADDPROPERTY           | \
+  nsIXPCScriptable::USE_JSSTUB_FOR_DELPROPERTY           | \
+  nsIXPCScriptable::USE_JSSTUB_FOR_SETPROPERTY           | \
+  nsIXPCScriptable::DONT_ENUM_QUERY_INTERFACE            | \
+  nsIXPCScriptable::CLASSINFO_INTERFACES_ONLY            | \
+  nsIXPCScriptable::DONT_REFLECT_INTERFACE_NAMES
+
+#include "xpc_map_end.h"
+
+NS_IMPL_THREADSAFE_ISUPPORTS3(nsDOMWorkerLocation, nsIWorkerLocation,
+                                                   nsIClassInfo,
+                                                   nsIXPCScriptable)
+
+NS_IMPL_CI_INTERFACE_GETTER1(nsDOMWorkerLocation, nsIWorkerLocation)
+
+NS_IMPL_THREADSAFE_DOM_CI_GETINTERFACES(nsDOMWorkerLocation)
+NS_IMPL_THREADSAFE_DOM_CI_ALL_THE_REST(nsDOMWorkerLocation)
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetHelperForLanguage(PRUint32 aLanguage,
+                                          nsISupports** _retval)
+{
+  if (aLanguage == nsIProgrammingLanguage::JAVASCRIPT) {
+    NS_ADDREF(*_retval = NS_ISUPPORTS_CAST(nsIWorkerLocation*, this));
+  }
+  else {
+    *_retval = nsnull;
+  }
+  return NS_OK;
+}
+
+// static
+already_AddRefed<nsIWorkerLocation>
+nsDOMWorkerLocation::NewLocation(nsIURL* aURL)
+{
+  NS_ASSERTION(aURL, "Don't hand me a null pointer!");
+
+  nsAutoPtr<nsDOMWorkerLocation> location(new nsDOMWorkerLocation());
+  NS_ENSURE_TRUE(location, nsnull);
+
+  nsresult rv = aURL->GetSpec(location->mHref);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+
+  rv = aURL->GetHost(location->mHostname);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+
+  rv = aURL->GetPath(location->mPathname);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+
+  nsCString temp;
+
+  rv = aURL->GetQuery(temp);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+  if (!temp.IsEmpty()) {
+    location->mSearch.AssignLiteral("?");
+    location->mSearch.Append(temp);
+  }
+
+  rv = aURL->GetRef(temp);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+
+  if (!temp.IsEmpty()) {
+    nsAutoString unicodeRef;
+
+    nsCOMPtr<nsITextToSubURI> converter =
+      do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
+    if (NS_SUCCEEDED(rv)) {
+      nsCString charset;
+      rv = aURL->GetOriginCharset(charset);
+      if (NS_SUCCEEDED(rv)) {
+        rv = converter->UnEscapeURIForUI(charset, temp, unicodeRef);
+        if (NS_SUCCEEDED(rv)) {
+          location->mHash.AssignLiteral("#");
+          location->mHash.Append(NS_ConvertUTF16toUTF8(unicodeRef));
+        }
+      }
+    }
+
+    if (NS_FAILED(rv)) {
+      location->mHash.AssignLiteral("#");
+      location->mHash.Append(temp);
+    }
+  }
+
+  rv = aURL->GetScheme(location->mProtocol);
+  NS_ENSURE_SUCCESS(rv, nsnull);
+
+  location->mProtocol.AppendLiteral(":");
+
+  PRInt32 port;
+  rv = aURL->GetPort(&port);
+  if (NS_SUCCEEDED(rv) && port != -1) {
+    location->mPort.AppendInt(port);
+
+    nsCAutoString host(location->mHostname);
+    host.AppendLiteral(":");
+    host.Append(location->mPort);
+
+    location->mHost.Assign(host);
+  }
+  else {
+    location->mHost.Assign(location->mHostname);
+  }
+
+  NS_ADDREF(location);
+  return location.forget();
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetHref(nsACString& aHref)
+{
+  aHref.Assign(mHref);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetProtocol(nsACString& aProtocol)
+{
+  aProtocol.Assign(mProtocol);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetHost(nsACString& aHost)
+{
+  aHost.Assign(mHost);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetHostname(nsACString& aHostname)
+{
+  aHostname.Assign(mHostname);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetPort(nsACString& aPort)
+{
+  aPort.Assign(mPort);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetPathname(nsACString& aPathname)
+{
+  aPathname.Assign(mPathname);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetSearch(nsACString& aSearch)
+{
+  aSearch.Assign(mSearch);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::GetHash(nsACString& aHash)
+{
+  aHash.Assign(mHash);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWorkerLocation::ToString(nsACString& _retval)
+{
+  return GetHref(_retval);
+}
diff --git a/dom/src/threads/nsDOMWorkerLocation.h b/dom/src/threads/nsDOMWorkerLocation.h
new file mode 100644
index 000000000000..e3832d20811b
--- /dev/null
+++ b/dom/src/threads/nsDOMWorkerLocation.h
@@ -0,0 +1,77 @@
+/* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is worker threads.
+ *
+ * The Initial Developer of the Original Code is
+ *   Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2009
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Ben Turner <bent.mozilla@gmail.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef __NSDOMWORKERLOCATION_H__
+#define __NSDOMWORKERLOCATION_H__
+
+#include "nsIClassInfo.h"
+#include "nsIDOMWorkers.h"
+#include "nsIXPCScriptable.h"
+
+#include "nsCOMPtr.h"
+#include "nsStringGlue.h"
+
+class nsIURL;
+
+class nsDOMWorkerLocation : public nsIWorkerLocation,
+                            public nsIClassInfo,
+                            public nsIXPCScriptable
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIWORKERLOCATION
+  NS_DECL_NSICLASSINFO
+  NS_DECL_NSIXPCSCRIPTABLE
+
+  static already_AddRefed<nsIWorkerLocation> NewLocation(nsIURL* aURL);
+
+protected:
+  nsDOMWorkerLocation() { }
+
+private:
+  nsCString mHref;
+  nsCString mProtocol;
+  nsCString mHost;
+  nsCString mHostname;
+  nsCString mPort;
+  nsCString mPathname;
+  nsCString mSearch;
+  nsCString mHash;
+};
+
+#endif /* __NSDOMWORKERLOCATION_H__ */
diff --git a/dom/src/threads/nsDOMWorkerScriptLoader.cpp b/dom/src/threads/nsDOMWorkerScriptLoader.cpp
index 6acda1c7c22c..5651a4bcd1ec 100644
--- a/dom/src/threads/nsDOMWorkerScriptLoader.cpp
+++ b/dom/src/threads/nsDOMWorkerScriptLoader.cpp
@@ -483,7 +483,9 @@ nsDOMWorkerScriptLoader::RunInternal()
 
       // Set the principal and URI on the new worker.
       mWorker->SetPrincipal(principal);
-      mWorker->SetURI(uri);
+
+      rv = mWorker->SetURI(uri);
+      NS_ENSURE_SUCCESS(rv, rv);
     }
     else {
       rv = secMan->CheckLoadURIWithPrincipal(principal, uri, 0);
diff --git a/dom/src/threads/test/Makefile.in b/dom/src/threads/test/Makefile.in
index 1ffd60ecd6c1..4771fac12540 100644
--- a/dom/src/threads/test/Makefile.in
+++ b/dom/src/threads/test/Makefile.in
@@ -66,6 +66,8 @@ _TEST_FILES = \
   importScripts_worker_imported4.js \
   test_json.html \
   json_worker.js \
+  test_location.html \
+  location_worker.js \
   test_longThread.html \
   longThread_worker.js \
   test_navigator.html \
diff --git a/dom/src/threads/test/location_worker.js b/dom/src/threads/test/location_worker.js
new file mode 100644
index 000000000000..a6b90e5f56ed
--- /dev/null
+++ b/dom/src/threads/test/location_worker.js
@@ -0,0 +1,4 @@
+for (var string in self.location) {
+  postMessage({ "string": string, "value": self.location[string] });
+}
+postMessage({"string": "testfinished", "value": self.location.toString()});
diff --git a/dom/src/threads/test/test_location.html b/dom/src/threads/test/test_location.html
new file mode 100644
index 000000000000..6524deed14e1
--- /dev/null
+++ b/dom/src/threads/test/test_location.html
@@ -0,0 +1,64 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Tests of DOM Worker Location
+-->
+<head>
+  <title>Test for DOM Worker Location</title>
+  <script type="text/javascript" src="/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script class="testbody" language="javascript">
+
+  var thisFilename = "test_location.html";
+  var workerFilename = "location_worker.js";
+
+  var href = window.location.href
+  var baseHref = href.substr(0, href.lastIndexOf("/") + 1);
+
+  var path = window.location.pathname;
+  var basePath = path.substr(0, path.lastIndexOf("/") + 1);
+
+  var strings = {
+    "href": baseHref + workerFilename,
+    "protocol": window.location.protocol,
+    "host": window.location.host,
+    "hostname": window.location.hostname,
+    "port": window.location.port,
+    "pathname": basePath + workerFilename,
+    "search": "",
+    "hash": ""
+  };
+
+  is(thisFilename, href.substr(href.lastIndexOf("/") + 1));
+
+  var worker = new Worker(workerFilename);
+
+  worker.onmessage = function(event) {
+    if (event.data.string == "testfinished") {
+      is(event.data.value, strings["href"]);
+      SimpleTest.finish();
+      return;
+    }
+    ok(event.data.string in strings);
+    is(event.data.value, strings[event.data.string]);
+  };
+
+  worker.onerror = function(event) {
+    ok(false, "Worker had an error: " + event.data);
+    SimpleTest.finish();
+  }
+
+  SimpleTest.waitForExplicitFinish();
+
+</script>
+</pre>
+</body>
+</html>