diff --git a/defines.hpp b/defines.hpp
index e486c3e3c5..54a1bf08e7 100644
--- a/defines.hpp
+++ b/defines.hpp
@@ -60,6 +60,7 @@
 #define CITY_ROADS_FILE_TAG "city_roads"
 #define DESCRIPTIONS_FILE_TAG "descriptions"
 #define MAXSPEEDS_FILE_TAG "maxspeeds"
+#define ROUTING_WORLD_FILE_TAG "routing_world"
 
 #define READY_FILE_EXTENSION ".ready"
 #define RESUME_FILE_EXTENSION ".resume"