diff --git a/lib/httputils.js b/lib/httputils.js
index 2491e5ee34a978b30c91aa53c4b69d772f89887d..671fa5a16554c0e36b46519611c4e774be7c9917 100644
--- a/lib/httputils.js
+++ b/lib/httputils.js
@@ -42,6 +42,16 @@ exports.forbidden = function(resp, reason)
   resp.end();
 };
 
+exports.throttled = function(resp, reason)
+{
+  resp.writeHead(429, {"Content-Type": "text/plain"});
+  resp.write("Too Many Requests");
+  if (reason) {
+    resp.write(": " + reason);
+  }
+  resp.end();
+};
+
 exports.jsonResponse = function(resp, obj)
 {
   resp.writeHead(200, {"Content-Type": "application/json"});
diff --git a/lib/wsapi/stage_email.js b/lib/wsapi/stage_email.js
index c5b562304f4ca262e5eff7b2e66e025bb435b783..9b4061bc8cba06187a672636e37eaaf85bf4dcdc 100644
--- a/lib/wsapi/stage_email.js
+++ b/lib/wsapi/stage_email.js
@@ -26,7 +26,7 @@ exports.process = function(req, res) {
     if (last && (new Date() - last) < config.get('min_time_between_emails_ms')) {
       logger.warn('throttling request to stage email address ' + req.body.email + ', only ' +
                   ((new Date() - last) / 1000.0) + "s elapsed");
-      return httputils.forbidden(res, "throttling.  try again later.");
+      return httputils.throttled(res, "Too many emails sent to that address, try again later.");
     }
 
     try {
diff --git a/lib/wsapi/stage_user.js b/lib/wsapi/stage_user.js
index dc5f0aef04cb392a3e02de3f31de20f450bf2242..580838037c2d40eee2c74117eb1f93830fed5f9d 100644
--- a/lib/wsapi/stage_user.js
+++ b/lib/wsapi/stage_user.js
@@ -31,7 +31,7 @@ exports.process = function(req, resp) {
     if (last && (new Date() - last) < config.get('min_time_between_emails_ms')) {
       logger.warn('throttling request to stage email address ' + req.body.email + ', only ' +
                   ((new Date() - last) / 1000.0) + "s elapsed");
-      return httputils.forbidden(resp, "throttling.  try again later.");
+      return httputils.throttled(resp, "Too many emails sent to that address, try again later.");
     }
 
     try {
diff --git a/resources/static/shared/network.js b/resources/static/shared/network.js
index a16b38df9b737888eb61b435ac5e0df12f4a7931..ce84f5616a89d131fbfccd70e9a04056af01f12e 100644
--- a/resources/static/shared/network.js
+++ b/resources/static/shared/network.js
@@ -186,8 +186,8 @@ BrowserID.Network = (function() {
           complete(onComplete, status.success);
         },
         error: function(info) {
-          // 403 is throttling.
-          if (info.network.status === 403) {
+          // 429 is throttling.
+          if (info.network.status === 429) {
             complete(onComplete, false);
           }
           else complete(onFailure, info);
@@ -392,8 +392,8 @@ BrowserID.Network = (function() {
           complete(onComplete, response.success);
         },
         error: function(info) {
-          // 403 is throttling.
-          if (info.network.status === 403) {
+          // 429 is throttling.
+          if (info.network.status === 429) {
             complete(onComplete, false);
           }
           else complete(onFailure, info);
diff --git a/resources/static/test/mocks/xhr.js b/resources/static/test/mocks/xhr.js
index e74cccc1a24659f5dd930d61bbb5cee7bb8c0db2..98428bd107d5d68827c12efea6746c28f5133c76 100644
--- a/resources/static/test/mocks/xhr.js
+++ b/resources/static/test/mocks/xhr.js
@@ -52,7 +52,7 @@ BrowserID.Mocks.xhr = (function() {
       "post /wsapi/stage_user unknown_secondary": { success: true },
       "post /wsapi/stage_user valid": { success: true },
       "post /wsapi/stage_user invalid": { success: false },
-      "post /wsapi/stage_user throttle": 403,
+      "post /wsapi/stage_user throttle": 429,
       "post /wsapi/stage_user ajaxError": undefined,
       "get /wsapi/user_creation_status?email=registered%40testuser.com pending": { status: "pending" },
       "get /wsapi/user_creation_status?email=registered%40testuser.com complete": { status: "complete" },
@@ -79,7 +79,7 @@ BrowserID.Mocks.xhr = (function() {
       "post /wsapi/stage_email unknown_secondary": { success: true },
       "post /wsapi/stage_email known_secondary": { success: true },
       "post /wsapi/stage_email invalid": { success: false },
-      "post /wsapi/stage_email throttle": 403,
+      "post /wsapi/stage_email throttle": 429,
       "post /wsapi/stage_email ajaxError": undefined,
       "post /wsapi/cert_key ajaxError": undefined,
       "get /wsapi/email_addition_status?email=registered%40testuser.com pending": { status: "pending" },
diff --git a/tests/email-throttling-test.js b/tests/email-throttling-test.js
index db6a7d1a38193463945238af2bcc1bd0626bf402..ba807a7829aa692ca705946e767ec9c461a7a7de 100755
--- a/tests/email-throttling-test.js
+++ b/tests/email-throttling-test.js
@@ -52,7 +52,7 @@ suite.addBatch({
       site:'fakesite.com'
     }),
     "is throttled": function(err, r) {
-      assert.strictEqual(r.code, 403);
+      assert.strictEqual(r.code, 429);
     }
   }
 });
@@ -101,8 +101,8 @@ suite.addBatch({
       email: 'second@fakeemail.com',
       site:'fakesite.com'
     }),
-    "is throttled with a 403": function(err, r) {
-      assert.strictEqual(r.code, 403);
+    "is throttled with a 429": function(err, r) {
+      assert.strictEqual(r.code, 429);
     }
   }
 });