diff --git a/src/command_func.h b/src/command_func.h
--- a/src/command_func.h
+++ b/src/command_func.h
@@ -91,6 +91,7 @@ CommandCallback CcGame;
 
 /* group_gui.cpp */
 CommandCallback CcCreateGroup;
+CommandCallback CcAddVehicleNewGroup;
 
 /* industry_gui.cpp */
 CommandCallback CcBuildIndustry;