diff -up ./src/ArraySerializable.php.php8 ./src/ArraySerializable.php
--- ./src/ArraySerializable.php.php8	2021-03-25 13:59:16.746513687 +0100
+++ ./src/ArraySerializable.php	2021-03-25 13:59:20.978497492 +0100
@@ -70,7 +70,7 @@ class ArraySerializable extends Abstract
             // Ensure any previously populated values not in the replacement
             // remain following population.
             if (is_callable([$object, 'getArrayCopy'])) {
-                $original = $object->getArrayCopy($object);
+                $original = $object->getArrayCopy();
                 $replacement = array_merge($original, $replacement);
             }
             $object->exchangeArray($replacement);