diff --git a/lib/AdminActions/Util/Logger.php b/lib/AdminActions/Util/Logger.php
index fa6b9a2..efffc43 100644
--- a/lib/AdminActions/Util/Logger.php
+++ b/lib/AdminActions/Util/Logger.php
@@ -220,7 +220,7 @@ class Logger {
                     break;
             }
 
-            $val = $data[$prefix.'arg'.($counter[$prefix]++)];
+            $val = $data[$prefix.'arg'.($counter[$prefix]++)] ?? null;
             if (!$refl_type->allowsNull() || !is_null($val))
                 $val = $field_types[$prefix]['unpacker']($val);