diff --git a/Configuration/TCA/tx_cal_event.php b/Configuration/TCA/tx_cal_event.php
index d147d91..7f9f801 100644
--- a/Configuration/TCA/tx_cal_event.php
+++ b/Configuration/TCA/tx_cal_event.php
@@ -1069,7 +1069,7 @@
 		'type' => 'select',
 		'renderMode' => 'tree',
 		'treeConfig' => array(
-			'dataProvider' => 'Tx_Cal_TreeProvider_DatabaseTreeDataProvider',
+			'dataProvider' => 'TYPO3\CMS\Cal\TreeProvider\DatabaseTreeDataProvider',
 			'parentField' => 'parent',
 			'appearance' => array(
 				'showHeader' => TRUE,
@@ -1093,4 +1093,4 @@
 	);
 }
 
-return $tx_cal_event;
\ No newline at end of file
+return $tx_cal_event;