diff --git a/src/statusbar_gui.cpp b/src/statusbar_gui.cpp
--- a/src/statusbar_gui.cpp
+++ b/src/statusbar_gui.cpp
@@ -25,6 +25,7 @@
 #include "toolbar_gui.h"
 #include "core/geometry_func.hpp"
 #include "zoom_func.h"
+#include "date_type.h"
 #include "timer/timer.h"
 #include "timer/timer_game_calendar.h"
 #include "timer/timer_window.h"