diff --git a/app/workers/functions.php b/app/workers/functions.php
index 2bf2216bd0..fcd0d624e4 100644
--- a/app/workers/functions.php
+++ b/app/workers/functions.php
@@ -357,7 +357,7 @@ class FunctionsV1 extends Worker
 
         \array_walk($vars, function (&$value, $key) {
             $key = $this->filterEnvKey($key);
-            $value = \escapeshellarg((empty($value)) ? 'null' : $value);
+            $value = \escapeshellarg((empty($value)) ? '' : $value);
             $value = "--env {$key}={$value}";
         });