diff --git a/src/articulated_vehicles.cpp b/src/articulated_vehicles.cpp
--- a/src/articulated_vehicles.cpp
+++ b/src/articulated_vehicles.cpp
@@ -14,6 +14,8 @@
 #include "roadveh.h"
 #include "newgrf_engine.h"
 #include "vehicle_func.h"
+#include "engine_base.h"
+#include "engine_func.h"
 
 #include "table/strings.h"
 #include "table/sprites.h"