diff --git a/lib/Group/backend.php b/lib/Group/backend.php
index c70bd6665c..f34c340be8 100644
--- a/lib/Group/backend.php
+++ b/lib/Group/backend.php
@@ -33,7 +33,7 @@ abstract class OC_GROUP_BACKEND {
 	 *
 	 * @param  string  $groupName  The name of the group to create
 	 */
-	abstract public static function createGroup($groupName);
+	public static function createGroup($groupName){}
 
 	/**
 	 * Check if a user belongs to a group
@@ -41,7 +41,7 @@ abstract class OC_GROUP_BACKEND {
 	 * @param  string  $username   Name of the user to check
 	 * @param  string  $groupName  Name of the group
 	 */
-	abstract public static function inGroup($username, $groupName);
+	public static function inGroup($username, $groupName){}
 
 	/**
 	 * Add a user to a group
@@ -49,7 +49,7 @@ abstract class OC_GROUP_BACKEND {
 	 * @param  string  $username   Name of the user to add to group
 	 * @param  string  $groupName  Name of the group in which add the user
 	 */
-	abstract public static function addToGroup($username, $groupName);
+	public static function addToGroup($username, $groupName){}
 
 	/**
 	 * Remove a user from a group
@@ -57,18 +57,18 @@ abstract class OC_GROUP_BACKEND {
 	 * @param  string  $username   Name of the user to remove from group
 	 * @param  string  $groupName  Name of the group from which remove the user
 	 */
-	abstract public static function removeFromGroup($username,$groupName);
+	public static function removeFromGroup($username,$groupName){}
 
 	/**
 	 * Get all groups the user belongs to
 	 *
 	 * @param  string  $username  Name of the user
 	 */
-	abstract public static function getUserGroups($username);
+	public static function getUserGroups($username){}
 
 	/**
 	 * get a list of all groups
 	 *
 	 */
-	abstract public static function getGroups();
+	public static function getGroups(){}
 }
diff --git a/lib/User/backend.php b/lib/User/backend.php
index ab053661f8..0483d72bf0 100644
--- a/lib/User/backend.php
+++ b/lib/User/backend.php
@@ -35,7 +35,7 @@ abstract class OC_USER_BACKEND {
 	 * @param  string  $username  The username of the user to create
 	 * @param  string  $password  The password of the new user
 	 */
-	abstract public static function createUser($username, $password);
+	public static function createUser($username, $password){}
 
 	/**
 	 * Try to login a user
@@ -43,18 +43,18 @@ abstract class OC_USER_BACKEND {
 	 * @param  string  $username  The username of the user to log in
 	 * @param  string  $password  The password of the user
 	 */
-	abstract public static function login($username, $password);
+	public static function login($username, $password){}
 
 	/**
 	 * Check if some user is logged in
 	 *
 	 */
-	abstract public static function isLoggedIn();
+	public static function isLoggedIn(){}
 
 	/**
 	 * Generate a random password
 	 */
-	abstract public static function generatePassword();
+	public static function generatePassword(){}
 
 	/**
 	 * Set the password of a user
@@ -62,7 +62,7 @@ abstract class OC_USER_BACKEND {
 	 * @param  string  $username  User who password will be changed
 	 * @param  string  $password  The new password for the user
 	 */
-	abstract public static function setPassword($username, $password);
+	public static function setPassword($username, $password){}
 
 	/**
 	 * Check if the password of the user is correct
@@ -70,12 +70,12 @@ abstract class OC_USER_BACKEND {
 	 * @param  string  $username  Name of the user
 	 * @param  string  $password  Password of the user
 	 */
-	abstract public static function checkPassword($username, $password);
+	public static function checkPassword($username, $password){}
 
 
 	/**
 	 * get a list of all users
 	 *
 	 */
-	abstract public static function getUsers();
+	public static function getUsers(){}
 }