diff --git a/src/settings_internal.h b/src/settings_internal.h
--- a/src/settings_internal.h
+++ b/src/settings_internal.h
@@ -85,7 +85,7 @@ struct SettingDesc {
 typedef SettingDesc SettingDescGlobVarList;
 
 const SettingDesc *GetSettingFromName(const char *name, uint *i);
-bool SetSettingValue(uint index, int32 value);
+bool SetSettingValue(uint index, int32 value, bool force_newgame = false);
 bool SetSettingValue(uint index, const char *value);
 void SetCompanySetting(uint index, int32 value);