diff --git a/apps/dav/lib/caldav/caldavbackend.php b/apps/dav/lib/caldav/caldavbackend.php
index bb50100d9a..79bbcefaab 100644
--- a/apps/dav/lib/caldav/caldavbackend.php
+++ b/apps/dav/lib/caldav/caldavbackend.php
@@ -138,6 +138,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	 * @return array
 	 */
 	function getCalendarsForUser($principalUri) {
+		$principalUriOriginal = $principalUri;
 		$principalUri = $this->convertPrincipal($principalUri, true);
 		$fields = array_values($this->propertyMap);
 		$fields[] = 'id';
@@ -184,7 +185,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		$stmt->closeCursor();
 
 		// query for shared calendars
-		$principals = $this->principalBackend->getGroupMembership($principalUri);
+		$principals = $this->principalBackend->getGroupMembership($principalUriOriginal, true);
 		$principals[]= $principalUri;
 
 		$fields = array_values($this->propertyMap);
diff --git a/apps/dav/lib/carddav/carddavbackend.php b/apps/dav/lib/carddav/carddavbackend.php
index bfb6ea82ad..ccf0f4fbe0 100644
--- a/apps/dav/lib/carddav/carddavbackend.php
+++ b/apps/dav/lib/carddav/carddavbackend.php
@@ -126,7 +126,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 		$result->closeCursor();
 
 		// query for shared calendars
-		$principals = $this->principalBackend->getGroupMembership($principalUri);
+		$principals = $this->principalBackend->getGroupMembership($principalUri, true);
 		$principals[]= $principalUri;
 
 		$query = $this->db->getQueryBuilder();
diff --git a/apps/dav/lib/connector/sabre/principal.php b/apps/dav/lib/connector/sabre/principal.php
index 31de4e5bad..49fb4efdee 100644
--- a/apps/dav/lib/connector/sabre/principal.php
+++ b/apps/dav/lib/connector/sabre/principal.php
@@ -135,7 +135,7 @@ class Principal implements BackendInterface {
 	 * @return array
 	 * @throws Exception
 	 */
-	public function getGroupMembership($principal) {
+	public function getGroupMembership($principal, $needGroups = false) {
 		list($prefix, $name) = URLUtil::splitPath($principal);
 
 		if ($prefix === $this->principalPrefix) {
@@ -144,7 +144,7 @@ class Principal implements BackendInterface {
 				throw new Exception('Principal not found');
 			}
 
-			if ($this->hasGroups) {
+			if ($this->hasGroups || $needGroups) {
 				$groups = $this->groupManager->getUserGroups($user);
 				$groups = array_map(function($group) {
 					/** @var IGroup $group */