diff --git a/application/Espo/Core/Application.php b/application/Espo/Core/Application.php
index 48569025c0..bb1c746471 100644
--- a/application/Espo/Core/Application.php
+++ b/application/Espo/Core/Application.php
@@ -83,7 +83,7 @@ class Application
      */
     public function run(string $className, ?object $params = null)
     {
-        if (!$className) {
+        if (!$className || !class_exists($className)) {
             $this->getLog()->error("Application runner '{$className}' does not exist.");
             return;
         }