diff --git a/lib/user.php b/lib/user.php
index 9dc8cca97a..76c4c45ee3 100644
--- a/lib/user.php
+++ b/lib/user.php
@@ -172,7 +172,7 @@ class OC_User {
 		}
 
 		// Check if user already exists
-		if( self::userExists($uid) ) {
+		if( self::userExistsForCreation($uid) ) {
 			throw new Exception('The username is already being used');
 		}
 
@@ -551,6 +551,19 @@ class OC_User {
 		return false;
 	}
 
+    public static function userExistsForCreation($uid) {
+        foreach(self::$_usedBackends as $backend) {
+            if(!$backend->implementsActions(OC_USER_BACKEND_CREATE_USER))
+                continue;
+
+            $result=$backend->userExists($uid);
+            if($result===true) {
+                return true;
+            }
+        }
+        return false;
+    }
+
 	/**
 	 * disables a user
 	 * @param string $userid the user to disable
diff --git a/settings/ajax/createuser.php b/settings/ajax/createuser.php
index 09ef25d92f..56653bed6b 100644
--- a/settings/ajax/createuser.php
+++ b/settings/ajax/createuser.php
@@ -26,12 +26,6 @@ if(OC_User::isAdminUser(OC_User::getUser())) {
 $username = $_POST["username"];
 $password = $_POST["password"];
 
-// Does the group exist?
-if(OC_User::userExists($username)) {
-	OC_JSON::error(array("data" => array( "message" => "User already exists" )));
-	exit();
-}
-
 // Return Success story
 try {
 	if (!OC_User::createUser($username, $password)) {
diff --git a/settings/js/users.js b/settings/js/users.js
index 094cddda29..3ab48675f2 100644
--- a/settings/js/users.js
+++ b/settings/js/users.js
@@ -400,12 +400,6 @@ $(document).ready(function () {
         event.preventDefault();
         var username = $('#newusername').val();
         var password = $('#newuserpassword').val();
-        if ($('#content table tbody tr').filterAttr('data-uid', username).length > 0) {
-            OC.dialogs.alert(
-                t('settings', 'The username is already being used'),
-                t('settings', 'Error creating user'));
-            return;
-        }
         if ($.trim(username) == '') {
             OC.dialogs.alert(
                 t('settings', 'A valid username must be provided'),