diff --git a/src/Utilities/URLHandling.php b/src/Utilities/URLHandling.php
index cd299d8..63da986 100644
--- a/src/Utilities/URLHandling.php
+++ b/src/Utilities/URLHandling.php
@@ -19,6 +19,6 @@ class URLHandling
                 return self::$URLBase . $name . ".json";
             }
         }
-        die();
+        throw new \Exception("Could not determine URL for schema " . $targetSchemaClassName . ".");
     }
 }