diff --git a/src/__tests__/LDClient-test.js b/src/__tests__/LDClient-test.js
index 00cefe7a..260010fe 100644
--- a/src/__tests__/LDClient-test.js
+++ b/src/__tests__/LDClient-test.js
@@ -71,6 +71,28 @@ describe('LDClient', function() {
       });
     });
 
+    it('should resolve waitUntilReady promise after ready event was already emitted', function(done) {
+      var user = { key: 'user' };
+      var handleInitialReady = sinon.spy();
+      var handleReady = sinon.spy();
+      var client = LDClient.initialize('UNKNOWN_ENVIRONMENT_ID', user, {
+        bootstrap: {}
+      });
+
+      client.on('ready', handleInitialReady);
+
+      setTimeout(function () {
+        client.waitUntilReady().then(handleReady);
+
+        setTimeout(function () {
+          expect(handleInitialReady.called).to.be.true;
+          expect(handleReady.called).to.be.true;
+          done();
+        }, 0);
+      }, 1000);
+    });
+
+
     it('should log an error when initialize is called without an environment key', function(done) {
       var user = {key: 'user'};
       var errorSpy = sinon.spy(console, 'error');
diff --git a/src/index.js b/src/index.js
index 937f12b5..a336da3f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -34,6 +34,8 @@ var flushInterval = 2000;
 
 var seenRequests = {};
 
+var ldPromise = Promise.reject(messages.clientNotReady());
+
 function sendIdentifyEvent(user) {
   enqueueEvent({
     kind: 'identify',
@@ -82,9 +84,7 @@ function sendGoalEvent(kind, goal) {
 }
 
 function waitUntilReady() {
-  return new Promise(function(resolve) {
-    client.on('ready', resolve);
-  });
+  return ldPromise;
 }
 
 function identify(user, hash, onDone) {
@@ -388,6 +388,11 @@ function initialize(env, user, options) {
 
   window.addEventListener('message', handleMessage);
 
+  var onReady = client.on('ready', function () {
+    ldPromise = Promise.resolve(client);
+    client.off(onReady);
+  });
+
   return client;
 }
 
diff --git a/src/messages.js b/src/messages.js
index 86086f8f..f68eba3c 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -1,4 +1,7 @@
 module.exports ={
+  clientNotReady: function() {
+    return 'LaunchDarkly client is not ready';
+  },
   invalidKey: function() {
     return 'Event key must be a string';
   },