diff --git a/UPGRADE.md b/UPGRADE.md
index 086d3ab8..32617b8d 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -1,5 +1,8 @@
 # Upgrade Notes
  
+## 5.0.3
+- Fix element type check in api channel [#423](https://github.com/dachcom-digital/pimcore-formbuilder/issues/423)
+
 ## 5.0.2
 - Fix Mail Layout Editor base path [#426](https://github.com/dachcom-digital/pimcore-formbuilder/issues/426)
 
diff --git a/src/OutputWorkflow/Channel/Api/ApiOutputChannelWorker.php b/src/OutputWorkflow/Channel/Api/ApiOutputChannelWorker.php
index 3b8d9a7d..b3ba625f 100644
--- a/src/OutputWorkflow/Channel/Api/ApiOutputChannelWorker.php
+++ b/src/OutputWorkflow/Channel/Api/ApiOutputChannelWorker.php
@@ -113,7 +113,7 @@ protected function buildApiNodes(array $nodes, array $formData, array $mapping,
             foreach ($apiMappingFields as $apiMappingField) {
 
                 $context = [
-                    'type'            => $formField['type'],
+                    'type'            => $formField['type'] ?? null,
                     'parentType'      => $hasParent ? $parentType : null,
                     'formData'        => $formData,
                     'formField'       => $formField,
@@ -121,6 +121,8 @@ protected function buildApiNodes(array $nodes, array $formData, array $mapping,
                 ];
 
                 $nodes[$apiMappingField] = $this->findFormFieldValue($formField, $fieldTransformer, $context);
+
+                unset($apiMappingField);
             }
 
             if ($hasChildren) {