diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 42df838523d8e..a147d785cc747 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -64,6 +64,7 @@
 use OCA\DAV\Events\SubscriptionCreatedEvent;
 use OCA\DAV\Events\SubscriptionDeletedEvent;
 use OCA\DAV\Events\SubscriptionUpdatedEvent;
+use OCP\Calendar\Exceptions\CalendarException;
 use OCP\DB\Exception;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\EventDispatcher\IEventDispatcher;
@@ -770,8 +771,14 @@ public function getSubscriptionById($subscriptionId) {
 	 * @param string $calendarUri
 	 * @param array $properties
 	 * @return int
+	 *
+	 * @throws CalendarException
 	 */
 	public function createCalendar($principalUri, $calendarUri, array $properties) {
+		if (strlen($calendarUri) > 255) {
+			throw new CalendarException('URI too long. Calendar not created');
+		}
+
 		$values = [
 			'principaluri' => $this->convertPrincipal($principalUri, true),
 			'uri' => $calendarUri,
diff --git a/apps/dav/lib/CardDAV/CardDavBackend.php b/apps/dav/lib/CardDAV/CardDavBackend.php
index 6b60d6701d47a..b4fdcf922dc45 100644
--- a/apps/dav/lib/CardDAV/CardDavBackend.php
+++ b/apps/dav/lib/CardDAV/CardDavBackend.php
@@ -389,6 +389,10 @@ public function updateAddressBook($addressBookId, \Sabre\DAV\PropPatch $propPatc
 	 * @throws BadRequest
 	 */
 	public function createAddressBook($principalUri, $url, array $properties) {
+		if (strlen($url) > 255) {
+			throw new BadRequest('URI too long. Address book not created');
+		}
+
 		$values = [
 			'displayname' => null,
 			'description' => null,