diff --git a/src/Plugin/Field/FieldFormatter/ColorboxFormatter.php b/src/Plugin/Field/FieldFormatter/ColorboxFormatter.php
index 13c410310dc774afd35bf28ce1f75e4cc842bd90..a00e250beb9b0035f0a7b25fb647314c00cc0d17 100644
--- a/src/Plugin/Field/FieldFormatter/ColorboxFormatter.php
+++ b/src/Plugin/Field/FieldFormatter/ColorboxFormatter.php
@@ -194,7 +194,7 @@ class ColorboxFormatter extends ImageFormatterBase implements ContainerFactoryPl
 
       $entity_type = '';
 
-      if (!empty($form['#entity_type'])) {
+      if (isset($form['#entity_type'] ) && !empty($form['#entity_type'])) {
         $entity_type = $form['#entity_type'];
       }
 
@@ -252,7 +252,7 @@ class ColorboxFormatter extends ImageFormatterBase implements ContainerFactoryPl
 
       $entity_type = '';
 
-      if (!empty($form['#entity_type'])) {
+      if (isset($form['#entity_type']) && !empty($form['#entity_type'])) {
         $entity_type = $form['#entity_type'];
       }