diff --git a/setup/mods.available/conf/zpush/backend_caldav.php b/setup/mods.available/conf/zpush/backend_caldav.php
index 1990539a..428461da 100644
--- a/setup/mods.available/conf/zpush/backend_caldav.php
+++ b/setup/mods.available/conf/zpush/backend_caldav.php
@@ -10,7 +10,7 @@ define('CALDAV_SERVER', 'NC_HOST');
 define('CALDAV_PORT', 'NC_PORT');
 define('CALDAV_PATH', 'NC_PREFIX/remote.php/dav/calendars/%u/');
 define('CALDAV_PERSONAL', 'PRINCIPAL');
-define('CALDAV_SUPPORTS_SYNC', false);
+define('CALDAV_SUPPORTS_SYNC', true);
 define('CALDAV_MAX_SYNC_PERIOD', 2147483647);
 
 ?>
diff --git a/setup/mods.available/conf/zpush/backend_carddav.php b/setup/mods.available/conf/zpush/backend_carddav.php
index fd328dbe..1777e97b 100644
--- a/setup/mods.available/conf/zpush/backend_carddav.php
+++ b/setup/mods.available/conf/zpush/backend_carddav.php
@@ -14,7 +14,7 @@ define('CARDDAV_DEFAULT_PATH', 'NC_PREFIX/remote.php/dav/addressbooks/users/%u/c
 define('CARDDAV_GAL_PATH', ''); /* readonly, searchable, not syncd */
 define('CARDDAV_GAL_MIN_LENGTH', 5);
 define('CARDDAV_CONTACTS_FOLDER_NAME', '%u Addressbook');
-define('CARDDAV_SUPPORTS_SYNC', false);
+define('CARDDAV_SUPPORTS_SYNC', true);
 
 // If the CardDAV server supports the FN attribute for searches
 // DAViCal supports it, but SabreDav, Nextcloud and SOGo don't