diff --git a/api/src/Contacts/Ads.php b/api/src/Contacts/Ads.php
index 811e28cf24..e836ed78ef 100644
--- a/api/src/Contacts/Ads.php
+++ b/api/src/Contacts/Ads.php
@@ -118,11 +118,8 @@ class Ads extends Ldap
 
 		// AD seems to use user, instead of inetOrgPerson
 		unset($this->schema2egw['posixaccount']);
-		$this->schema2egw['user'] = array_merge($this->schema2egw['inetorgperson'], array(
+		$this->schema2egw['user'] = array_merge($this->schema2egw['organizantionalperson'], array(
 			'account_id'	=> 'objectsid',
-			'id'            => 'objectguid',
-			'uid'			=> 'objectguid',
-			'n_fn'          => 'displayname',	// leave CN used in DN untouched
 			'accountexpires', 'useraccountcontrol',	// needed to exclude deactivated or expired accounts
 		));
 		unset($this->schema2egw['user']['n_fileas']);
@@ -160,7 +157,7 @@ class Ads extends Ldap
 	{
 		// check that GUID eg. from URL contains only valid hex characters and dash
 		// we cant use ldap::quote() for win2008r2 hex GUID, as it contains backslashes
-		if (!preg_match('/^[0-9A-Fa-f-]+/', $contact_id))
+		if (strlen($contact_id) !== 36 || !preg_match('/^[0-9A-F]{8}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{12}$/i', $contact_id))
 		{
 			throw new Api\Exception\AssertionFailed("'$contact_id' is NOT a valid GUID!");
 		}
diff --git a/api/src/Contacts/Ldap.php b/api/src/Contacts/Ldap.php
index 8100947d03..bcdc42a30d 100644
--- a/api/src/Contacts/Ldap.php
+++ b/api/src/Contacts/Ldap.php
@@ -158,7 +158,39 @@ class Ldap
 			'uid'			=> 'entryuuid',
 			'id'			=> 'uid',
 		),
-
+		'organizantionalperson' => [	// ActiveDirectory
+			'n_fn'			=> 'displayname',	// to leave CN as part of DN untouched
+			'n_given'		=> 'givenname',
+			'n_family'		=> 'sn',
+			//'sound'			=> 'audio',
+			'note'			=> 'description',
+			'url'			=> 'url',
+			'org_name'		=> 'company',
+			'org_unit'		=> 'department',
+			'title'			=> 'title',
+			'adr_one_street'		=> 'streetaddress',
+			'adr_one_locality'		=> 'l',
+			'adr_one_region'		=> 'st',
+			'adr_one_postalcode'	=> 'postalcode',
+			'adr_one_countryname'	=> 'co',
+			'adr_one_countrycode'	=> 'countrycode',
+			'tel_work'		=> 'telephonenumber',
+			'tel_home'		=> 'homephone',
+			'tel_fax'		=> 'facsimiletelephonenumber',
+			'tel_cell'		=> 'mobile',
+			'tel_pager'		=> 'pager',
+			'tel_other'		=> 'othertelephone',
+			'tel_cell_private' => 'othermobile',
+			'assistent'		=> 'assistant',
+			'email'			=> 'mail',
+			'room'			=> 'roomnumber',
+			'jpegphoto'		=> 'jpegphoto',
+			'n_fileas'		=> 'displayname',
+			'label'			=> 'postaladdress',
+			'pubkey'		=> 'usersmimecertificate',
+			'uid'			=> 'objectguid',
+			'id'			=> 'objectguid',
+		],
 		#displayName
 		#mozillaCustom1
 		#mozillaCustom2