-char doopt[] = { IAC, DO, '%', 'c', 0 };
-char dont[] = { IAC, DONT, '%', 'c', 0 };
-char will[] = { IAC, WILL, '%', 'c', 0 };
-char wont[] = { IAC, WONT, '%', 'c', 0 };
+unsigned char doopt[] = { IAC, DO, '%', 'c', 0 };
+unsigned char dont[] = { IAC, DONT, '%', 'c', 0 };
+unsigned char will[] = { IAC, WILL, '%', 'c', 0 };
+unsigned char wont[] = { IAC, WONT, '%', 'c', 0 };