diff --git a/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php b/typo3/sysext/form/Classes/Domain/Finishers/FinisherVariableProvider.php
index 07e707c2519eeb762e1e442fc17b36e5d87a1b16..25230025671dc36c4d1825c865425b6d2cd6a0d6 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;
         }