diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28b4f08c..3e12a3c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,23 @@
+x.y.z Release notes
+=============================================================
+### Breaking changes
+* None
+
+### Enhancements
+* None
+
+### Bug fixes
+* When authentication fails due to a misbehaving server, a proper error is thrown.
+
+### Internal
+* None
+
 2.0.12 Release notes (2017-12-1)
 =============================================================
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * None
 
 ### Bug fixes
@@ -18,12 +32,12 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * None
 
 ### Bug fixes
 * [Object Server] Fixed a bug where deleted-then-recreated objects with identical primary keys to become empty.
-* [Object Server] Fixed a bug in outward partial sync is changed to ensure convergence of partial sync in the case where the client creates a primary key object, that is already present on the server, and subscribes to it in the same transaction. 
+* [Object Server] Fixed a bug in outward partial sync is changed to ensure convergence of partial sync in the case where the client creates a primary key object, that is already present on the server, and subscribes to it in the same transaction.
 
 ### Internal
 * Updated to Realm Sync 2.1.7 (see under "Bug fixes").
@@ -33,7 +47,7 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * None
 
 ### Bug fixes
@@ -47,7 +61,7 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * None
 
 ### Bug fixes
@@ -61,7 +75,7 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * [Object Server] Improving performance of processing large changesets.
 
 ### Bug fixes
@@ -76,7 +90,7 @@
 ### Breaking changes
 * None
 
-### Enchancements
+### Enhancements
 * None
 
 ### Bug fixes
@@ -91,7 +105,7 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * Improved notification performance for objects with no object or list properties.
 
 ### Bug fixes
@@ -107,7 +121,7 @@
 ### Breaking changes
 * None.
 
-### Enchancements
+### Enhancements
 * None.
 
 ### Bug fixes
diff --git a/lib/user-methods.js b/lib/user-methods.js
index 3ec76eba..b0f4210c 100644
--- a/lib/user-methods.js
+++ b/lib/user-methods.js
@@ -154,7 +154,15 @@ function _authenticate(userConstructor, server, json, callback) {
 
     const promise = performFetch(url, options)
         .then((response) => {
-            if (response.status !== 200) {
+            const contentType = response.headers.get('Content-Type');
+            if (contentType.indexOf('application/json') === -1) {
+                return response.text().then((body) => {
+                    throw new AuthError({
+                        title: `Could not authenticate: Realm Object Server didn't respond with valid JSON`,
+                        body,
+                    });
+                });
+            } else if (!response.ok) {
                 return response.json().then((body) => Promise.reject(new AuthError(body)));
             } else {
                 return response.json().then(function (body) {
diff --git a/tests/js/user-tests.js b/tests/js/user-tests.js
index b1c02b3a..404ba1fa 100644
--- a/tests/js/user-tests.js
+++ b/tests/js/user-tests.js
@@ -160,6 +160,20 @@ module.exports = {
       .catch((e) => assertIsError(e));
   },
 
+  testLoginTowardsMisbehavingServer() {
+    const username = uuid();
+
+    // Try authenticating towards a server thats clearly not ROS
+    return Realm.Sync.User.register('https://github.com/realm/realm-js', username, 'user')
+      .catch((e) => {
+        assertIsError(e);
+        TestCase.assertEqual(
+          e.message,
+          "Could not authenticate: Realm Object Server didn't respond with valid JSON"
+        );
+      });
+  },
+
   testAll() {
     const all = Realm.Sync.User.all;
     TestCase.assertArrayLength(Object.keys(all), 0);
@@ -324,4 +338,3 @@ module.exports = {
   }, */
 
 };
-