diff --git a/core/server/middleware/auth.js b/core/server/middleware/auth.js
index 43837f1762..ea746b90c2 100644
--- a/core/server/middleware/auth.js
+++ b/core/server/middleware/auth.js
@@ -1,9 +1,10 @@
-var _           = require('lodash'),
-    passport    = require('passport'),
-    url         = require('url'),
-    errors      = require('../errors'),
-    config      = require('../config'),
-    labs        = require('../utils/labs'),
+var _             = require('lodash'),
+    passport      = require('passport'),
+    url           = require('url'),
+    errors        = require('../errors'),
+    config        = require('../config'),
+    labs          = require('../utils/labs'),
+    isDevelopment,
     oauthServer,
 
     auth;
@@ -36,10 +37,14 @@ function isBearerAutorizationHeader(req) {
 }
 
 function isValidOrigin(origin, client) {
+    isDevelopment = process.env.NODE_ENV === 'development';
+
     if (origin && client && client.type === 'ua' && (
         _.some(client.trustedDomains, {trusted_domain: origin})
         || origin === url.parse(config.url).hostname
         || origin === url.parse(config.urlSSL ? config.urlSSL : '').hostname
+        || (origin === '127.0.0.1' && isDevelopment)
+        || (origin === 'localhost' && isDevelopment)
     )) {
         return true;
     } else {
@@ -70,7 +75,8 @@ auth = {
 
         return passport.authenticate(['oauth2-client-password'], {session: false, failWithError: false},
             function authenticate(err, client) {
-                var origin = null;
+                var origin = null,
+                    error;
                 if (err) {
                     return next(err); // will generate a 500 error
                 }
@@ -94,7 +100,12 @@ auth = {
                     req.client = client;
                     return next(null, client);
                 } else {
-                    return errors.handleAPIError(new errors.UnauthorizedError('Access denied.'), req, res, next);
+                    error = new errors.UnauthorizedError('Access Denied from url: ' + origin + '. Please use the url configured in config.js.');
+                    errors.logError(error,
+                        'You have attempted to access your Ghost admin panel from a url that does not appear in config.js.',
+                        'For information on how to fix this, please visit http://support.ghost.org/config/#url.'
+                    );
+                    return errors.handleAPIError(error, req, res, next);
                 }
             }
         )(req, res, next);
diff --git a/core/test/unit/middleware/authentication_spec.js b/core/test/unit/middleware/authentication_spec.js
index 136fbcb7f6..bfaf99856c 100644
--- a/core/test/unit/middleware/authentication_spec.js
+++ b/core/test/unit/middleware/authentication_spec.js
@@ -406,6 +406,54 @@ describe('Auth', function () {
             done();
         });
 
+        it('should authenticate client with origin `localhost` while in development', function (done) {
+            var resetEnvironment = auth.__set__('process.env.NODE_ENV', 'development');
+            req.body = {};
+            req.body.client_id = testClient;
+            req.body.client_secret = testSecret;
+            req.headers = {};
+            req.headers.origin = 'http://localhost';
+
+            res.header = {};
+
+            sandbox.stub(res, 'header', function (key, value) {
+                key.should.equal('Access-Control-Allow-Origin');
+                value.should.equal('http://localhost');
+            });
+
+            registerSuccessfulClientPasswordStrategy();
+            auth.authenticateClient(req, res, next);
+
+            next.called.should.be.true;
+            next.calledWith(null, client).should.be.true;
+            resetEnvironment();
+            done();
+        });
+
+        it('shouldn\'t authenticate client with origin `localhost` by default', function (done) {
+            req.body = {};
+            req.body.client_id = testClient;
+            req.body.client_secret = testSecret;
+            req.headers = {};
+            req.headers.origin = 'http://localhost';
+
+            res.status = {};
+
+            sandbox.stub(res, 'status', function (statusCode) {
+                statusCode.should.eql(401);
+                return {
+                    json: function (err) {
+                        err.errors[0].errorType.should.eql('UnauthorizedError');
+                    }
+                };
+            });
+
+            registerSuccessfulClientPasswordStrategy();
+            auth.authenticateClient(req, res, next);
+            next.called.should.be.false;
+            done();
+        });
+
         it('should authenticate client with id in query', function (done) {
             req.body = {};
             req.query = {};