diff --git a/apps/dav/lib/CalDAV/ResourceBooking/AbstractPrincipalBackend.php b/apps/dav/lib/CalDAV/ResourceBooking/AbstractPrincipalBackend.php
index 90d147f674..bc96041d91 100644
--- a/apps/dav/lib/CalDAV/ResourceBooking/AbstractPrincipalBackend.php
+++ b/apps/dav/lib/CalDAV/ResourceBooking/AbstractPrincipalBackend.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * @copyright 2018, Georg Ehrke <oc.list@georgehrke.com>
+ * @copyright 2019, Georg Ehrke <oc.list@georgehrke.com>
  *
  * @author Georg Ehrke <oc.list@georgehrke.com>
  *
@@ -50,6 +50,12 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 	/** @var string */
 	private $dbTableName;
 
+	/** @var string */
+	private $dbMetaDataTableName;
+
+	/** @var string */
+	private $dbForeignKeyName;
+
 	/** @var string */
 	private $cuType;
 
@@ -74,7 +80,9 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 		$this->groupManager = $groupManager;
 		$this->logger = $logger;
 		$this->principalPrefix = $principalPrefix;
-		$this->dbTableName = 'calendar_' . $dbPrefix;
+		$this->dbTableName = 'calendar_' . $dbPrefix . 's';
+		$this->dbMetaDataTableName = $this->dbTableName . '_md';
+		$this->dbForeignKeyName = $dbPrefix . '_id';
 		$this->cuType = $cuType;
 	}
 
@@ -100,8 +108,31 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 				->from($this->dbTableName);
 			$stmt = $query->execute();
 
+			$metaDataQuery = $this->db->getQueryBuilder();
+			$metaDataQuery->select([$this->dbForeignKeyName, 'key', 'value'])
+				->from($this->dbMetaDataTableName);
+			$metaDataStmt = $metaDataQuery->execute();
+			$metaDataRows = $metaDataStmt->fetchAll(\PDO::FETCH_ASSOC);
+
+			$metaDataById = [];
+			foreach($metaDataRows as $metaDataRow) {
+				if (!isset($metaDataById[$metaDataRow[$this->dbForeignKeyName]])) {
+					$metaDataById[$metaDataRow[$this->dbForeignKeyName]] = [];
+				}
+
+				$metaDataById[$metaDataRow[$this->dbForeignKeyName]][$metaDataRow['key']] =
+					$metaDataRow['value'];
+			}
+
 			while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
-				$principals[] = $this->rowToPrincipal($row);
+				$id = $row['id'];
+
+				if (isset($metaDataById[$id])) {
+					$principals[] = $this->rowToPrincipal($row, $metaDataById[$id]);
+				} else {
+					$principals[] = $this->rowToPrincipal($row);
+				}
+
 			}
 
 			$stmt->closeCursor();
@@ -138,7 +169,19 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 			return null;
 		}
 
-		return $this->rowToPrincipal($row);
+		$metaDataQuery = $this->db->getQueryBuilder();
+		$metaDataQuery->select(['key', 'value'])
+			->from($this->dbMetaDataTableName)
+			->where($metaDataQuery->expr()->eq($this->dbForeignKeyName, $metaDataQuery->createNamedParameter($row['id'])));
+		$metaDataStmt = $metaDataQuery->execute();
+		$metaDataRows = $metaDataStmt->fetchAll(\PDO::FETCH_ASSOC);
+		$metadata = [];
+
+		foreach($metaDataRows as $metaDataRow) {
+			$metadata[$metaDataRow['key']] = $metaDataRow['value'];
+		}
+
+		return $this->rowToPrincipal($row, $metadata);
 	}
 
 	/**
@@ -338,14 +381,18 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 
 	/**
 	 * convert database row to principal
+	 *
+	 * @param String[] $row
+	 * @param String[] $metadata
+	 * @return Array
 	 */
-	private function rowToPrincipal($row) {
-		return [
+	private function rowToPrincipal(array $row, array $metadata=[]):array {
+		return array_merge([
 			'uri' => $this->principalPrefix . '/' . $row['backend_id'] . '-' . $row['resource_id'],
 			'{DAV:}displayname' => $row['displayname'],
 			'{http://sabredav.org/ns}email-address' => $row['email'],
 			'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->cuType,
-		];
+		], $metadata);
 	}
 
 	/**
@@ -353,7 +400,7 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 	 * @param $userGroups
 	 * @return bool
 	 */
-	private function isAllowedToAccessResource($row, $userGroups) {
+	private function isAllowedToAccessResource(array $row, array $userGroups):bool {
 		if (!isset($row['group_restrictions']) ||
 			$row['group_restrictions'] === null ||
 			$row['group_restrictions'] === '') {
diff --git a/apps/dav/lib/CalDAV/ResourceBooking/ResourcePrincipalBackend.php b/apps/dav/lib/CalDAV/ResourceBooking/ResourcePrincipalBackend.php
index f8f10e78f9..0f6e6e7b4f 100644
--- a/apps/dav/lib/CalDAV/ResourceBooking/ResourcePrincipalBackend.php
+++ b/apps/dav/lib/CalDAV/ResourceBooking/ResourcePrincipalBackend.php
@@ -40,6 +40,6 @@ class ResourcePrincipalBackend extends AbstractPrincipalBackend {
 								IGroupManager $groupManager,
 								ILogger $logger) {
 		parent::__construct($dbConnection, $userSession, $groupManager, $logger,
-			'principals/calendar-resources', 'resources', 'RESOURCE');
+			'principals/calendar-resources', 'resource', 'RESOURCE');
 	}
 }
diff --git a/apps/dav/lib/CalDAV/ResourceBooking/RoomPrincipalBackend.php b/apps/dav/lib/CalDAV/ResourceBooking/RoomPrincipalBackend.php
index 3059ed80ea..68a344aa0c 100644
--- a/apps/dav/lib/CalDAV/ResourceBooking/RoomPrincipalBackend.php
+++ b/apps/dav/lib/CalDAV/ResourceBooking/RoomPrincipalBackend.php
@@ -40,6 +40,6 @@ class RoomPrincipalBackend extends AbstractPrincipalBackend {
 								IGroupManager $groupManager,
 								ILogger $logger) {
 		parent::__construct($dbConnection, $userSession, $groupManager, $logger,
-			'principals/calendar-rooms', 'rooms', 'ROOM');
+			'principals/calendar-rooms', 'room', 'ROOM');
 	}
 }