diff --git a/system/modules/DocumentManagementSystemFileTypeSets/dca/tl_dms_file_type_sets.php b/system/modules/DocumentManagementSystemFileTypeSets/dca/tl_dms_file_type_sets.php
index <HASH>..<HASH> 100644
--- a/system/modules/DocumentManagementSystemFileTypeSets/dca/tl_dms_file_type_sets.php
+++ b/system/modules/DocumentManagementSystemFileTypeSets/dca/tl_dms_file_type_sets.php
@@ -271,7 +271,7 @@ class tl_dms_file_type_sets extends Backend
 			foreach ($GLOBALS['TL_DCA']['tl_dms_file_type_sets']['fields']['published']['save_callback'] as $callback)
 			{
 				$this->import($callback[0]);
-				$blnVisible = $this->$callback[0]->$callback[1]($blnVisible, $this);
+				$blnVisible = $this->{$callback[0]}->{$callback[1]}($blnVisible, $this);
 			}
 		}
Adjust the code to be compatible with PHP7 (closes #5)