diff --git a/code/ryzom/server/src/entities_game_service/stdpch.h b/code/ryzom/server/src/entities_game_service/stdpch.h
index 23529b27a..a40fb9b59 100644
--- a/code/ryzom/server/src/entities_game_service/stdpch.h
+++ b/code/ryzom/server/src/entities_game_service/stdpch.h
@@ -37,6 +37,7 @@
 #include <string>
 #include <utility>
 #include <vector>
+#include <functional>
 
 // NeL georges
 #include "nel/georges/load_form.h"