diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/OpenIdModule.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/OpenIdModule.java
index f6ef51a..6f2caa3 100644
--- a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/OpenIdModule.java
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/OpenIdModule.java
@@ -42,6 +42,8 @@
     });
 
     serve("/" + OpenIdServiceImpl.RETURN_URL).with(OpenIdLoginServlet.class);
+    serve("/" + XrdsServlet.LOCATION).with(XrdsServlet.class);
+    filter("/").through(XrdsFilter.class);
 
     install(new RpcServletModule(RpcServletModule.PREFIX) {
       @Override
diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsFilter.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsFilter.java
new file mode 100644
index 0000000..92230f6
--- /dev/null
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsFilter.java
@@ -0,0 +1,42 @@
+package com.google.gerrit.httpd.auth.openid;
+
+import com.google.gerrit.server.config.CanonicalWebUrl;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+import java.io.IOException;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletResponse;
+
+@Singleton
+class XrdsFilter implements Filter {
+  private final Provider<String> url;
+
+  @Inject
+  XrdsFilter(@CanonicalWebUrl final Provider<String> url) {
+    this.url = url;
+  }
+
+  @Override
+  public void doFilter(ServletRequest request, ServletResponse response,
+      FilterChain chain) throws IOException, ServletException {
+    HttpServletResponse rsp = (HttpServletResponse) response;
+    rsp.setHeader("X-XRDS-Location", url.get() + XrdsServlet.LOCATION);
+    chain.doFilter(request, response);
+  }
+
+  @Override
+  public void init(FilterConfig config) {
+  }
+
+  @Override
+  public void destroy() {
+  }
+}
diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsServlet.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsServlet.java
new file mode 100644
index 0000000..5bcb852
--- /dev/null
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/openid/XrdsServlet.java
@@ -0,0 +1,71 @@
+// Copyright (C) 2010 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.httpd.auth.openid;
+
+import com.google.gerrit.server.config.CanonicalWebUrl;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+import java.io.IOException;
+
+import javax.servlet.ServletOutputStream;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@Singleton
+class XrdsServlet extends HttpServlet {
+  private static final String ENC = "UTF-8";
+  static final String LOCATION = "OpenID.XRDS";
+
+  private final Provider<String> url;
+
+  @Inject
+  XrdsServlet(@CanonicalWebUrl final Provider<String> url) {
+    this.url = url;
+  }
+
+  @Override
+  protected void doGet(HttpServletRequest req, HttpServletResponse rsp)
+      throws IOException {
+    final StringBuilder r = new StringBuilder();
+    r.append("<?xml version=\"1.0\" encoding=\"" + ENC + "\"?>");
+    r.append("<xrds:XRDS");
+    r.append(" xmlns:xrds=\"xri://$xrds\"");
+    r.append(" xmlns:openid=\"http://openid.net/xmlns/1.0\"");
+    r.append(" xmlns=\"xri://$xrd*($v*2.0)\">");
+    r.append("<XRD>");
+    r.append("<Service priority=\"1\">");
+    r.append("<Type>http://specs.openid.net/auth/2.0/return_to</Type>");
+    r.append("<URI>" + url.get() + OpenIdServiceImpl.RETURN_URL + "</URI>");
+    r.append("</Service>");
+    r.append("</XRD>");
+    r.append("</xrds:XRDS>");
+    r.append("\n");
+
+    final byte[] raw = r.toString().getBytes(ENC);
+    rsp.setContentLength(raw.length);
+    rsp.setContentType("application/xrds+xml");
+    rsp.setCharacterEncoding(ENC);
+
+    final ServletOutputStream out = rsp.getOutputStream();
+    try {
+      out.write(raw);
+    } finally {
+      out.close();
+    }
+  }
+}