diff --git a/src/citymania/cm_main.cpp b/src/citymania/cm_main.cpp
index ed511de0aa..290bf3eb76 100644
--- a/src/citymania/cm_main.cpp
+++ b/src/citymania/cm_main.cpp
@@ -6,6 +6,7 @@
 #include "cm_minimap.hpp"
 
 #include "../network/network_func.h"
+#include "../timer/timer.h"
 #include "../window_func.h"
 
 #include "../safeguards.h"