diff --git a/src/vehicle.cpp b/src/vehicle.cpp
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -42,6 +42,8 @@
 #include "order.h"
 #include "strings_func.h"
 #include "zoom_func.h"
+#include "functions.h"
+#include "window_func.h"
 
 #define INVALID_COORD (0x7fffffff)
 #define GEN_HASH(x, y) ((GB((y), 6, 6) << 6) + GB((x), 7, 6))