diff --git a/lib/client.js b/lib/client.js
index 8f36af911..3334564a7 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -935,14 +935,17 @@ MatrixClient.prototype.login = function(loginType, data, callback) {
 MatrixClient.prototype.register = function(username, password,
                                            session_id, auth, callback) {
     if (auth === undefined) { auth = {}; }
-    auth.session = session_id;
+    if (session_id) auth.session = session_id;
+
+    var params = {
+        auth: auth
+    };
+    if (username !== undefined) params.username = username;
+    if (password !== undefined ) params.password = password;
+
     return this._http.requestWithPrefix(
         callback, "POST", "/register", undefined,
-        {
-            username: username,
-            password: password,
-            auth: auth
-        }, httpApi.PREFIX_V2_ALPHA
+        params, httpApi.PREFIX_V2_ALPHA
     );
 };
 
@@ -1389,16 +1392,18 @@ function _PojoToMatrixEventMapper(plainOldJsObject) {
  * @param {string} email
  * @param {string} client_secret
  * @param {string} send_attempt
+ * @param {string} next_link Optional
  * @param {module:client.callback} callback Optional.
  * @return {module:client.Promise} Resolves: TODO
  * @return {module:http-api.MatrixError} Rejects: with an error response.
  */
 MatrixClient.prototype.requestEmailToken = function(email, client_secret,
-                                                    send_attempt, callback) {
+                                                    send_attempt, next_link, callback) {
     var params = {
         client_secret: client_secret,
         email: email,
-        send_attempt: send_attempt
+        send_attempt: send_attempt,
+        next_link: next_link
     };
     return this._http.idServerRequest(
         callback, "POST", "/validate/email/requestToken",