Index: backend.h
--- backend.h.orig
+++ backend.h
@@ -242,7 +242,7 @@ extern GameInfo gameInfo;
 
 /* ICS vars used with backend.c and zippy.c */
 enum ICS_TYPE { ICS_GENERIC, ICS_ICC, ICS_FICS, ICS_CHESSNET /* not really supported */ };
-enum ICS_TYPE ics_type;
+extern enum ICS_TYPE ics_type;
 
 /* pgntags.c prototypes
  */
