extern char *yy_text; /* Needed because yytext can be either a char[]
or a (non-constant) char* */
extern int yyoffset P((void));
-extern char initialRights[BOARD_SIZE];
-extern char castlingRights[MAX_MOVES][BOARD_SIZE];
+extern signed char initialRights[BOARD_SIZE];
+extern signed char castlingRights[MAX_MOVES][BOARD_SIZE];