diff --git a/phpBB/phpbb/event/kernel_exception_subscriber.php b/phpBB/phpbb/event/kernel_exception_subscriber.php
index 9d15f9370e..1ee771cfe7 100644
--- a/phpBB/phpbb/event/kernel_exception_subscriber.php
+++ b/phpBB/phpbb/event/kernel_exception_subscriber.php
@@ -61,7 +61,7 @@ class kernel_exception_subscriber implements EventSubscriberInterface
 		$exception = $event->getException();
 
 		$message = $exception->getMessage();
-		$this->type_caster->set_var($message, $message, 'string', false, false);
+		$this->type_caster->set_var($message, $message, 'string', true, false);
 
 		if ($exception instanceof \phpbb\exception\exception_interface)
 		{