diff --git a/framework/core/src/Frontend/Frontend.php b/framework/core/src/Frontend/Frontend.php
index 1f4be210fe..7cb9e34614 100644
--- a/framework/core/src/Frontend/Frontend.php
+++ b/framework/core/src/Frontend/Frontend.php
@@ -27,7 +27,7 @@ public function __construct(
     ) {
     }
 
-    public function content(callable $callback, int $priority): void
+    public function content(callable $callback, int $priority = 0): void
     {
         $this->content[] = compact('callback', 'priority');
     }