diff --git a/ajax/event/edit.form.php b/ajax/event/edit.form.php
index 24f7d08d..ecba697c 100644
--- a/ajax/event/edit.form.php
+++ b/ajax/event/edit.form.php
@@ -27,7 +27,7 @@ $vevent = $object->VEVENT;
 $dtstart = $vevent->DTSTART;
 $dtend = OC_Calendar_Object::getDTEndFromVEvent($vevent);
 switch($dtstart->getDateType()) {
-	case Sabre_VObject_Property_DateTime::UTC:
+	case Sabre\VObject\Property\DateTime::UTC:
 		$timeOffset = $_SESSION['timezone']*60;
 		$newDT      = $dtstart->getDateTime();
 		$newDT->add(new DateInterval("PT" . $timeOffset . "M"));
@@ -35,15 +35,15 @@ switch($dtstart->getDateType()) {
 		$newDT      = $dtend->getDateTime();
 		$newDT->add(new DateInterval("PT" . $timeOffset . "M"));
 		$dtend->setDateTime($newDT);
-	case Sabre_VObject_Property_DateTime::LOCALTZ:
-	case Sabre_VObject_Property_DateTime::LOCAL:
+	case Sabre\VObject\Property\DateTime::LOCALTZ:
+	case Sabre\VObject\Property\DateTime::LOCAL:
 		$startdate = $dtstart->getDateTime()->format('d-m-Y');
 		$starttime = $dtstart->getDateTime()->format('H:i');
 		$enddate = $dtend->getDateTime()->format('d-m-Y');
 		$endtime = $dtend->getDateTime()->format('H:i');
 		$allday = false;
 		break;
-	case Sabre_VObject_Property_DateTime::DATE:
+	case Sabre\VObject\Property\DateTime::DATE:
 		$startdate = $dtstart->getDateTime()->format('d-m-Y');
 		$starttime = '';
 		$dtend->getDateTime()->modify('-1 day');
diff --git a/ajax/event/move.php b/ajax/event/move.php
index 2ba6d7f1..646814f9 100644
--- a/ajax/event/move.php
+++ b/ajax/event/move.php
@@ -24,19 +24,19 @@ $dtstart = $vevent->DTSTART;
 $dtend = OC_Calendar_Object::getDTEndFromVEvent($vevent);
 $start_type = $dtstart->getDateType();
 $end_type = $dtend->getDateType();
-if ($allday && $start_type != Sabre_VObject_Property_DateTime::DATE) {
-	$start_type = $end_type = Sabre_VObject_Property_DateTime::DATE;
+if ($allday && $start_type != Sabre\VObject\Property\DateTime::DATE) {
+	$start_type = $end_type = Sabre\VObject\Property\DateTime::DATE;
 	$dtend->setDateTime($dtend->getDateTime()->modify('+1 day'), $end_type);
 }
-if (!$allday && $start_type == Sabre_VObject_Property_DateTime::DATE) {
-	$start_type = $end_type = Sabre_VObject_Property_DateTime::LOCALTZ;
+if (!$allday && $start_type == Sabre\VObject\Property\DateTime::DATE) {
+	$start_type = $end_type = Sabre\VObject\Property\DateTime::LOCALTZ;
 }
 $dtstart->setDateTime($dtstart->getDateTime()->add($delta), $start_type);
 $dtend->setDateTime($dtend->getDateTime()->add($delta), $end_type);
 unset($vevent->DURATION);
 
-$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre_VObject_Property_DateTime::UTC);
-$vevent->setDateTime('DTSTAMP', 'now', Sabre_VObject_Property_DateTime::UTC);
+$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre\VObject\Property\DateTime::UTC);
+$vevent->setDateTime('DTSTAMP', 'now', Sabre\VObject\Property\DateTime::UTC);
 
 try {
 	OC_Calendar_Object::edit($id, $vcalendar->serialize());
diff --git a/ajax/event/resize.php b/ajax/event/resize.php
index 46328c30..dcc0c7ed 100644
--- a/ajax/event/resize.php
+++ b/ajax/event/resize.php
@@ -31,8 +31,8 @@ $end_type = $dtend->getDateType();
 $dtend->setDateTime($dtend->getDateTime()->add($delta), $end_type);
 unset($vevent->DURATION);
 
-$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre_VObject_Property_DateTime::UTC);
-$vevent->setDateTime('DTSTAMP', 'now', Sabre_VObject_Property_DateTime::UTC);
+$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre\VObject\Property\DateTime::UTC);
+$vevent->setDateTime('DTSTAMP', 'now', Sabre\VObject\Property\DateTime::UTC);
 
 OC_Calendar_Object::edit($id, $vcalendar->serialize());
 $lastmodified = $vevent->__get('LAST-MODIFIED')->getDateTime();
diff --git a/lib/app.php b/lib/app.php
index ab6fae78..5bd8e83c 100644
--- a/lib/app.php
+++ b/lib/app.php
@@ -378,7 +378,7 @@ class OC_Calendar_App{
 		$vevent = $object->VEVENT;
 		$return = array();
 		$id = $event['id'];
-		$allday = ($vevent->DTSTART->getDateType() == Sabre_VObject_Element_DateTime::DATE)?true:false;
+		$allday = ($vevent->DTSTART->getDateType() == Sabre\VObject\Property\DateTime::DATE)?true:false;
 		$last_modified = @$vevent->__get('LAST-MODIFIED');
 		$lastmodified = ($last_modified)?$last_modified->getDateTime()->format('U'):0;
 		$staticoutput = array('id'=>(int)$event['id'],
@@ -410,7 +410,7 @@ class OC_Calendar_App{
 				$object->expand($start, $end);
 			}
 			foreach($object->getComponents() as $singleevent) {
-				if(!($singleevent instanceof Sabre_VObject_Component_VEvent)) {
+				if(!($singleevent instanceof Sabre\VObject\Component\VEvent)) {
 					continue;
 				}
 				$dynamicoutput = OC_Calendar_Object::generateStartEndDate($singleevent->DTSTART, OC_Calendar_Object::getDTEndFromVEvent($singleevent), $allday, self::$tz);
diff --git a/lib/export.php b/lib/export.php
index d8b919a8..96787709 100644
--- a/lib/export.php
+++ b/lib/export.php
@@ -74,11 +74,11 @@ class OC_Calendar_Export{
 			$start_dt = $dtstart->getDateTime();
 			$dtend = OC_Calendar_Object::getDTEndFromVEvent($object->VEVENT);
 			$end_dt = $dtend->getDateTime();
-			if($dtstart->getDateType() !== Sabre_VObject_Element_DateTime::DATE) {
+			if($dtstart->getDateType() !== Sabre\VObject\Element\DateTime::DATE) {
 				$start_dt->setTimezone(new DateTimeZone('UTC'));
 				$end_dt->setTimezone(new DateTimeZone('UTC'));
-				$object->VEVENT->setDateTime('DTSTART', $start_dt, Sabre_VObject_Property_DateTime::UTC);
-				$object->VEVENT->setDateTime('DTEND', $end_dt, Sabre_VObject_Property_DateTime::UTC);
+				$object->VEVENT->setDateTime('DTSTART', $start_dt, Sabre\VObject\Property\DateTime::UTC);
+				$object->VEVENT->setDateTime('DTEND', $end_dt, Sabre\VObject\Property\DateTime::UTC);
 			}
 			return $object->VEVENT->serialize();
 		}
diff --git a/lib/import.php b/lib/import.php
index a62c0152..b9a5fd01 100644
--- a/lib/import.php
+++ b/lib/import.php
@@ -20,7 +20,7 @@ class OC_Calendar_Import{
 	private $cacheprogress;
 
 	/*
-	 * @brief Sabre_VObject_Component_VCalendar object - for documentation see http://code.google.com/p/sabredav/wiki/Sabre_VObject_Component_VCalendar
+	 * @brief Sabre\VObject\Component\VCalendar object - for documentation see http://code.google.com/p/sabredav/wiki/Sabre_VObject_Component_VCalendar
 	 */
 	private $calobject;
 
@@ -108,7 +108,7 @@ class OC_Calendar_Import{
 		}
 		$numofcomponents = count($this->calobject->getComponents());
 		foreach($this->calobject->getComponents() as $object) {
-			if(!($object instanceof Sabre_VObject_Component_VEvent) && !($object instanceof Sabre_VObject_Component_VJournal) && !($object instanceof Sabre_VObject_Component_VTodo)) {
+			if(!($object instanceof Sabre\VObject\Component\VEvent) && !($object instanceof Sabre\VObject\Component\VJournal) && !($object instanceof Sabre\VObject\Component\VTodo)) {
 				continue;
 			}
 			$dtend = OC_Calendar_Object::getDTEndFromVEvent($object);
diff --git a/lib/object.php b/lib/object.php
index 3ad8dcb2..db654e80 100644
--- a/lib/object.php
+++ b/lib/object.php
@@ -754,7 +754,7 @@ class OC_Calendar_Object{
 		$vevent = new OC_VObject('VEVENT');
 		$vcalendar->add($vevent);
 
-		$vevent->setDateTime('CREATED', 'now', Sabre_VObject_Property_DateTime::UTC);
+		$vevent->setDateTime('CREATED', 'now', Sabre\VObject\Property\DateTime::UTC);
 
 		$vevent->setUID();
 		return self::updateVCalendarFromRequest($request, $vcalendar);
@@ -923,22 +923,22 @@ class OC_Calendar_Object{
 		}
 
 
-		$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre_VObject_Property_DateTime::UTC);
-		$vevent->setDateTime('DTSTAMP', 'now', Sabre_VObject_Property_DateTime::UTC);
+		$vevent->setDateTime('LAST-MODIFIED', 'now', Sabre\VObject\Property\DateTime::UTC);
+		$vevent->setDateTime('DTSTAMP', 'now', Sabre\VObject\Property\DateTime::UTC);
 		$vevent->setString('SUMMARY', $title);
 
 		if($allday) {
 			$start = new DateTime($from);
 			$end = new DateTime($to.' +1 day');
-			$vevent->setDateTime('DTSTART', $start, Sabre_VObject_Property_DateTime::DATE);
-			$vevent->setDateTime('DTEND', $end, Sabre_VObject_Property_DateTime::DATE);
+			$vevent->setDateTime('DTSTART', $start, Sabre\VObject\Property\DateTime::DATE);
+			$vevent->setDateTime('DTEND', $end, Sabre\VObject\Property\DateTime::DATE);
 		}else{
 			$timezone = OC_Calendar_App::getTimezone();
 			$timezone = new DateTimeZone($timezone);
 			$start = new DateTime($from.' '.$fromtime, $timezone);
 			$end = new DateTime($to.' '.$totime, $timezone);
-			$vevent->setDateTime('DTSTART', $start, Sabre_VObject_Property_DateTime::LOCALTZ);
-			$vevent->setDateTime('DTEND', $end, Sabre_VObject_Property_DateTime::LOCALTZ);
+			$vevent->setDateTime('DTSTART', $start, Sabre\VObject\Property\DateTime::LOCALTZ);
+			$vevent->setDateTime('DTEND', $end, Sabre\VObject\Property\DateTime::LOCALTZ);
 		}
 		unset($vevent->DURATION);
 
diff --git a/lib/repeat.php b/lib/repeat.php
index 641b1576..a613697d 100644
--- a/lib/repeat.php
+++ b/lib/repeat.php
@@ -95,10 +95,10 @@ class OC_Calendar_Repeat{
 		$end->modify('+5 years');
 		$object->expand($start, $end);
 		foreach($object->getComponents() as $vevent) {
-			if(!($vevent instanceof Sabre_VObject_Component_VEvent)) {
+			if(!($vevent instanceof Sabre\VObject\Component\VEvent)) {
 				continue;
 			}
-			$startenddate = OC_Calendar_Object::generateStartEndDate($vevent->DTSTART, OC_Calendar_Object::getDTEndFromVEvent($vevent), ($vevent->DTSTART->getDateType() == Sabre_VObject_Element_DateTime::DATE)?true:false, 'UTC');
+			$startenddate = OC_Calendar_Object::generateStartEndDate($vevent->DTSTART, OC_Calendar_Object::getDTEndFromVEvent($vevent), ($vevent->DTSTART->getDateType() == Sabre\VObject\Property\DateTime::DATE)?true:false, 'UTC');
 			$stmt = OCP\DB::prepare('INSERT INTO `*PREFIX*calendar_repeat` (`eventid`,`calid`,`startdate`,`enddate`) VALUES(?,?,?,?)');
 			$stmt->execute(array($id,OC_Calendar_Object::getCalendarid($id),$startenddate['start'],$startenddate['end']));
 		}
diff --git a/lib/search.php b/lib/search.php
index 5d313aec..4fda70a1 100644
--- a/lib/search.php
+++ b/lib/search.php
@@ -29,7 +29,7 @@ class OC_Search_Provider_Calendar extends OC_Search_Provider{
 					$start_dt->setTimezone(new DateTimeZone($user_timezone));
 					$end_dt = $dtend->getDateTime();
 					$end_dt->setTimezone(new DateTimeZone($user_timezone));
-					if ($dtstart->getDateType() == Sabre_VObject_Property_DateTime::DATE) {
+					if ($dtstart->getDateType() == Sabre\VObject\Property\DateTime::DATE) {
 						$end_dt->modify('-1 sec');
 						if($start_dt->format('d.m.Y') != $end_dt->format('d.m.Y')) {
 							$info = $l->t('Date') . ': ' . $start_dt->format('d.m.Y') . ' - ' . $end_dt->format('d.m.Y');