diff --git a/apps/admin_dependencies_chk/settings.php b/apps/admin_dependencies_chk/settings.php
index ea1ce9fb3dc..0cebc10198f 100644
--- a/apps/admin_dependencies_chk/settings.php
+++ b/apps/admin_dependencies_chk/settings.php
@@ -84,7 +84,7 @@ foreach($modules as $key => $module) {
 	if($enabled == false) unset($modules[$key]);
 }
 
-OC_UTIL::addStyle('admin_dependencies_chk', 'style');
+OCP\UTIL::addStyle('admin_dependencies_chk', 'style');
 $tmpl->assign( 'items', $modules );
 
 return $tmpl->fetchPage();
diff --git a/apps/bookmarks/index.php b/apps/bookmarks/index.php
index 4d604a4fd55..d36321a1ef9 100644
--- a/apps/bookmarks/index.php
+++ b/apps/bookmarks/index.php
@@ -30,7 +30,7 @@ OC_Util::checkAppEnabled('bookmarks');
 OC_App::setActiveNavigationEntry( 'bookmarks_index' );
 
 OC_Util::addScript('bookmarks','bookmarks');
-OC_Util::addStyle('bookmarks', 'bookmarks');
+OCP\Util::addStyle('bookmarks', 'bookmarks');
 
 $tmpl = new OC_Template( 'bookmarks', 'list', 'user' );
 
diff --git a/apps/calendar/appinfo/app.php b/apps/calendar/appinfo/app.php
index 21d128e7b8a..ccd7ff4c1a0 100644
--- a/apps/calendar/appinfo/app.php
+++ b/apps/calendar/appinfo/app.php
@@ -10,7 +10,7 @@ OC::$CLASSPATH['OC_Search_Provider_Calendar'] = 'apps/calendar/lib/search.php';
 OC_HOOK::connect('OC_User', 'post_deleteUser', 'OC_Calendar_Hooks', 'deleteUser');
 OC_Util::addScript('calendar','loader');
 OC_Util::addScript("3rdparty", "chosen/chosen.jquery.min");
-OC_Util::addStyle("3rdparty", "chosen/chosen");
+OCP\Util::addStyle("3rdparty", "chosen/chosen");
 OC_App::register( array(
   'order' => 10,
   'id' => 'calendar',
@@ -22,4 +22,4 @@ OC_App::addNavigationEntry( array(
   'icon' => OC_Helper::imagePath( 'calendar', 'icon.svg' ),
   'name' => $l->t('Calendar')));
 OC_App::registerPersonal('calendar', 'settings');
-OC_Search::registerProvider('OC_Search_Provider_Calendar');
\ No newline at end of file
+OC_Search::registerProvider('OC_Search_Provider_Calendar');
diff --git a/apps/calendar/index.php b/apps/calendar/index.php
index 417d2b6c225..6bb7cfd6865 100644
--- a/apps/calendar/index.php
+++ b/apps/calendar/index.php
@@ -40,16 +40,16 @@ if(OC_Preferences::getValue(OC_USER::getUser(), 'calendar', 'currentview', 'mont
 }
 
 OC_Util::addScript('3rdparty/fullcalendar', 'fullcalendar');
-OC_Util::addStyle('3rdparty/fullcalendar', 'fullcalendar');
+OCP\Util::addStyle('3rdparty/fullcalendar', 'fullcalendar');
 OC_Util::addScript('3rdparty/timepicker', 'jquery.ui.timepicker');
-OC_Util::addStyle('3rdparty/timepicker', 'jquery.ui.timepicker');
+OCP\Util::addStyle('3rdparty/timepicker', 'jquery.ui.timepicker');
 if(OC_Preferences::getValue(OC_USER::getUser(), "calendar", "timezone") == null || OC_Preferences::getValue(OC_USER::getUser(), 'calendar', 'timezonedetection') == 'true'){
 	OC_UTIL::addScript('calendar', 'geo');
 }
 OC_Util::addScript('calendar', 'calendar');
-OC_Util::addStyle('calendar', 'style');
+OCP\Util::addStyle('calendar', 'style');
 OC_Util::addScript('', 'jquery.multiselect');
-OC_Util::addStyle('', 'jquery.multiselect');
+OCP\Util::addStyle('', 'jquery.multiselect');
 OC_Util::addScript('contacts','jquery.multi-autocomplete');
 OC_Util::addScript('','oc-vcategories');
 OC_App::setActiveNavigationEntry('calendar_index');
diff --git a/apps/contacts/index.php b/apps/contacts/index.php
index 61cec6c24a8..0abec096e7f 100644
--- a/apps/contacts/index.php
+++ b/apps/contacts/index.php
@@ -52,10 +52,10 @@ OC_Util::addScript('contacts','jquery.combobox');
 OC_Util::addScript('contacts','jquery.inview');
 OC_Util::addScript('contacts','jquery.Jcrop');
 OC_Util::addScript('contacts','jquery.multi-autocomplete');
-OC_Util::addStyle('','jquery.multiselect');
-OC_Util::addStyle('contacts','jquery.combobox');
-OC_Util::addStyle('contacts','jquery.Jcrop');
-OC_Util::addStyle('contacts','contacts');
+OCP\Util::addStyle('','jquery.multiselect');
+OCP\Util::addStyle('contacts','jquery.combobox');
+OCP\Util::addStyle('contacts','jquery.Jcrop');
+OCP\Util::addStyle('contacts','contacts');
 
 $tmpl = new OC_Template( "contacts", "index", "user" );
 $tmpl->assign('uploadMaxFilesize', $maxUploadFilesize);
diff --git a/apps/external/appinfo/app.php b/apps/external/appinfo/app.php
index 74e6d5c94c6..7f8ef3043bc 100644
--- a/apps/external/appinfo/app.php
+++ b/apps/external/appinfo/app.php
@@ -22,7 +22,7 @@
  */
 
 OC::$CLASSPATH['OC_External'] = 'apps/external/lib/external.php';
-OC_Util::addStyle( 'external', 'style');
+OCP\Util::addStyle( 'external', 'style');
 
 OC_APP::registerAdmin('external', 'settings');
 
@@ -32,4 +32,4 @@ $sites = OC_External::getSites();
 for ($i = 0; $i < sizeof($sites); $i++) {
 	OC_App::addNavigationEntry(
 			array('id' => 'external_index' . ($i + 1), 'order' => 80 + $i, 'href' => OC_Helper::linkTo('external', 'index.php') . '?id=' . ($i + 1), 'icon' => OC_Helper::imagePath('external', 'external.png'), 'name' => $sites[$i][0]));
-}
\ No newline at end of file
+}
diff --git a/apps/files/index.php b/apps/files/index.php
index 8464db30f01..65a428a6c9d 100644
--- a/apps/files/index.php
+++ b/apps/files/index.php
@@ -25,7 +25,7 @@
 OC_Util::checkLoggedIn();
 
 // Load the files we need
-OC_Util::addStyle( "files", "files" );
+OCP\Util::addStyle( "files", "files" );
 OC_Util::addScript( "files", "jquery.iframe-transport" );
 OC_Util::addScript( "files", "jquery.fileupload" );
 OC_Util::addScript( "files", "files" );
diff --git a/apps/files/settings.php b/apps/files/settings.php
index 41017c064ef..5016630d192 100644
--- a/apps/files/settings.php
+++ b/apps/files/settings.php
@@ -29,7 +29,7 @@
 OC_Util::checkLoggedIn();
 
 // Load the files we need
-OC_Util::addStyle( "files", "files" );
+OCP\Util::addStyle( "files", "files" );
 OC_Util::addScript( "files", "files" );
 
 // Load the files
diff --git a/apps/files_encryption/lib/crypt.php b/apps/files_encryption/lib/crypt.php
index 8cf9451c63c..3968a2836a2 100644
--- a/apps/files_encryption/lib/crypt.php
+++ b/apps/files_encryption/lib/crypt.php
@@ -91,7 +91,7 @@ class OC_Crypt {
 	}
 
 	public static function changekeypasscode($oldPassword, $newPassword) {
-		if(OC_User::isLoggedIn()){
+		if(OCP\User::isLoggedIn()){
 			$username=OC_USER::getUser();
 			$view=new OC_FilesystemView('/'.$username);
 
diff --git a/apps/files_imageviewer/appinfo/app.php b/apps/files_imageviewer/appinfo/app.php
index 0f77076b79b..cf357d2e318 100644
--- a/apps/files_imageviewer/appinfo/app.php
+++ b/apps/files_imageviewer/appinfo/app.php
@@ -3,6 +3,6 @@
 OC_Util::addScript( 'files_imageviewer', 'lightbox' );
 OC_Util::addScript('files_imageviewer', 'jquery.mousewheel-3.0.4.pack');
 OC_Util::addScript('files_imageviewer', 'jquery.fancybox-1.3.4.pack');
-OC_Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
+OCP\Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
 
 ?>
diff --git a/apps/files_pdfviewer/appinfo/app.php b/apps/files_pdfviewer/appinfo/app.php
index 0f0b40764d9..fbcb30bb973 100644
--- a/apps/files_pdfviewer/appinfo/app.php
+++ b/apps/files_pdfviewer/appinfo/app.php
@@ -1,7 +1,7 @@
 <?php
 //load the required files
 OC_Util::addScript( 'files_pdfviewer', 'viewer');
-OC_Util::addStyle( 'files_pdfviewer', 'viewer');
+OCP\Util::addStyle( 'files_pdfviewer', 'viewer');
 OC_Util::addScript( 'files_pdfviewer', 'pdfjs/build/pdf');
 OC_Util::addScript( 'files_pdfviewer', 'pdfview');
 ?>
diff --git a/apps/files_sharing/appinfo/app.php b/apps/files_sharing/appinfo/app.php
index 645f4f5e4f2..7c547be3ca1 100644
--- a/apps/files_sharing/appinfo/app.php
+++ b/apps/files_sharing/appinfo/app.php
@@ -15,7 +15,7 @@ if ($dir != '/Shared' || OC_Appconfig::getValue('files_sharing', 'resharing', 'y
 	OC_Util::addScript("files_sharing", "share");
 }
 OC_Util::addScript("3rdparty", "chosen/chosen.jquery.min");
-OC_Util::addStyle( 'files_sharing', 'sharing' );
-OC_Util::addStyle("3rdparty", "chosen/chosen");
+OCP\Util::addStyle( 'files_sharing', 'sharing' );
+OCP\Util::addStyle("3rdparty", "chosen/chosen");
 
-?>
\ No newline at end of file
+?>
diff --git a/apps/files_sharing/get.php b/apps/files_sharing/get.php
index 3e42bf6a6c7..fbcb265fc03 100644
--- a/apps/files_sharing/get.php
+++ b/apps/files_sharing/get.php
@@ -49,7 +49,7 @@ if ($source !== false) {
 			}
 		}
 		// Load the files we need
-		OC_Util::addStyle("files", "files");
+		OCP\Util::addStyle("files", "files");
 		$breadcrumbNav = new OC_Template("files", "part.breadcrumb", "");
 		$breadcrumbNav->assign("breadcrumb", $breadcrumb);
 		$breadcrumbNav->assign("baseURL", OC_Helper::linkTo("files_sharing", "get.php")."?token=".$token."&path=");
diff --git a/apps/files_texteditor/appinfo/app.php b/apps/files_texteditor/appinfo/app.php
index 1bf09b5da2a..b3937236ecd 100644
--- a/apps/files_texteditor/appinfo/app.php
+++ b/apps/files_texteditor/appinfo/app.php
@@ -1,6 +1,6 @@
 <?php
 //load the required files
-OC_Util::addStyle( 'files_texteditor', 'style' );
+OCP\Util::addStyle( 'files_texteditor', 'style' );
 OC_Util::addScript( 'files_texteditor', 'editor');
 OC_Util::addScript( 'files_texteditor', 'aceeditor/ace');
-?>
\ No newline at end of file
+?>
diff --git a/apps/files_versions/history.php b/apps/files_versions/history.php
index 5e1949bf540..16ad92b90da 100644
--- a/apps/files_versions/history.php
+++ b/apps/files_versions/history.php
@@ -23,7 +23,7 @@
 require_once( '../../lib/base.php' );
 
 OC_Util::checkLoggedIn( );
-OC_Util::addStyle('files_versions','versions');
+OCP\Util::addStyle('files_versions','versions');
 $tmpl = new OC_Template( 'files_versions', 'history', 'user' );
 
 if ( isset( $_GET['path'] ) ) {
diff --git a/apps/gallery/templates/index.php b/apps/gallery/templates/index.php
index 43ba5131864..cf3d9188e65 100644
--- a/apps/gallery/templates/index.php
+++ b/apps/gallery/templates/index.php
@@ -1,12 +1,12 @@
 <?php
-OC_Util::addStyle('gallery', 'styles');
+OCP\Util::addStyle('gallery', 'styles');
 OC_Util::addScript('gallery', 'albums');
 OC_Util::addScript('gallery', 'scanner');
 OC_Util::addScript('gallery', 'album_cover');
-OC_Util::addStyle('files', 'files');
+OCP\Util::addStyle('files', 'files');
 OC_Util::addScript('files_imageviewer', 'jquery.mousewheel-3.0.4.pack');
 OC_Util::addScript('files_imageviewer', 'jquery.fancybox-1.3.4.pack');
-OC_Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
+OCP\Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
 $l = OC_L10N::get('gallery');
 ?>
 <script type="text/javascript">var gallery_scanning_root='<? echo OC_Preferences::getValue(OC_User::getUser(), 'gallery', 'root', '/'); ?>'; var gallery_default_order = '<? echo OC_Preferences::getValue(OC_User::getUser(), 'gallery', 'order', 'ASC'); ?>';</script>
diff --git a/apps/gallery/templates/view_album.php b/apps/gallery/templates/view_album.php
index f938e487954..9abfef901d2 100644
--- a/apps/gallery/templates/view_album.php
+++ b/apps/gallery/templates/view_album.php
@@ -1,10 +1,10 @@
 <?php
-OC_Util::addStyle('gallery', 'styles');
+OCP\Util::addStyle('gallery', 'styles');
 OC_Util::addScript('gallery', 'albums');
 OC_Util::addScript('gallery', 'album_cover');
 OC_Util::addScript('files_imageviewer', 'jquery.mousewheel-3.0.4.pack');
 OC_Util::addScript('files_imageviewer', 'jquery.fancybox-1.3.4.pack');
-OC_Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
+OCP\Util::addStyle( 'files_imageviewer', 'jquery.fancybox-1.3.4' );
 $l = OC_L10N::get('gallery');
 ?>
 <script type="text/javascript">
diff --git a/apps/media/index.php b/apps/media/index.php
index cdb347628bf..a102068740c 100644
--- a/apps/media/index.php
+++ b/apps/media/index.php
@@ -37,7 +37,7 @@ OC_Util::addScript('media','playlist');
 OC_Util::addScript('media','collection');
 OC_Util::addScript('media','scanner');
 OC_Util::addScript('media','jquery.jplayer.min');
-OC_Util::addStyle('media','music');
+OCP\Util::addStyle('media','music');
 
 OC_App::setActiveNavigationEntry( 'media_index' );
 
diff --git a/apps/user_ldap/settings.php b/apps/user_ldap/settings.php
index 2226c74609d..16e452fe156 100644
--- a/apps/user_ldap/settings.php
+++ b/apps/user_ldap/settings.php
@@ -23,7 +23,7 @@
 $params = array('ldap_host', 'ldap_port', 'ldap_dn', 'ldap_password', 'ldap_base', 'ldap_base_users', 'ldap_base_groups', 'ldap_userlist_filter', 'ldap_login_filter', 'ldap_display_name', 'ldap_tls', 'ldap_nocase'. 'ldap_quota_def', 'ldap_quota_attr', 'ldap_email_attr');
 
 OC_Util::addScript('user_ldap', 'settings');
-OC_Util::addStyle('user_ldap', 'settings');
+OCP\Util::addStyle('user_ldap', 'settings');
 
 if ($_POST) {
 	foreach($params as $param){