diff --git a/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php b/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php
index 6b77ae9d6e6a9bdf3604e38677b733e5e5b46726..e6a3682b7be4129954fe9052d1134d3161b19053 100644
--- a/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php
+++ b/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php
@@ -97,7 +97,7 @@ final class FinisherVariableProvider implements \ArrayAccess, \IteratorAggregate
     public function exists($finisherIdentifier, $key): bool
     {
         try {
-            ArrayUtility::getValueByPath($this->objects[$finisherIdentifier], $key, '.');
+            ArrayUtility::getValueByPath($this->objects[$finisherIdentifier] ?? [], $key, '.');
         } catch (MissingArrayPathException $e) {
             return false;
         }