diff --git a/routes/web.php b/routes/web.php
index ad8b622bdf..b86573620d 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -21,7 +21,9 @@
 
 declare(strict_types=1);
 
-const DATEFORMAT = '(19|20)[0-9]{2}-[0-9]{2}-[0-9]{2}';
+if(!defined('DATEFORMAT')) {
+    const DATEFORMAT = '(19|20)[0-9]{2}-[0-9]{2}-[0-9]{2}';
+}
 
 Route::group(
     ['namespace' => 'FireflyIII\Http\Controllers\System',