diff --git a/src/Slider.php b/src/Slider.php
index d3c61d3..3271d40 100644
--- a/src/Slider.php
+++ b/src/Slider.php
@@ -51,7 +51,7 @@ public function toggleVisibility($intId, $blnVisible)
 		$this->createInitialVersion('tl_rocksolid_slide', $intId);
 
 		// Trigger the save_callback
-		if (is_array($GLOBALS['TL_DCA']['tl_rocksolid_slide']['fields']['published']['save_callback'])) {
+		if (is_array($GLOBALS['TL_DCA']['tl_rocksolid_slide']['fields']['published']['save_callback'] ?? null)) {
 			foreach ($GLOBALS['TL_DCA']['tl_rocksolid_slide']['fields']['published']['save_callback'] as $callback) {
 				$this->import($callback[0]);
 				$blnVisible = $this->{$callback[0]}->{$callback[1]}($blnVisible, $this);