diff --git a/src/airport_gui.cpp b/src/airport_gui.cpp
--- a/src/airport_gui.cpp
+++ b/src/airport_gui.cpp
@@ -23,6 +23,7 @@
 #include "tilehighlight_func.h"
 #include "company_base.h"
 #include "station_type.h"
+#include "newgrf_airport.h"
 
 #include "table/sprites.h"
 #include "table/strings.h"