diff --git a/src/Plugin/migrate/process/EntityLookup.php b/src/Plugin/migrate/process/EntityLookup.php
index b2c8fd50d6ace40c854319b1f3ec46e121f802cf..8d6f4962fad0e69274fe155f34aaba7ef7421c9d 100644
--- a/src/Plugin/migrate/process/EntityLookup.php
+++ b/src/Plugin/migrate/process/EntityLookup.php
@@ -97,7 +97,7 @@ class EntityLookup extends ProcessPluginBase implements ContainerFactoryPluginIn
   protected ?string $destinationBundleKey = NULL;
   protected ?string $lookupValueKey = NULL;
   protected ?string $lookupBundleKey = NULL;
-  protected mixed $lookupBundle = NULL;
+  protected $lookupBundle = NULL;
   protected ?string $lookupEntityType = NULL;
   protected ?string $destinationProperty;
   protected bool $accessCheck = TRUE;