#define icon_width 32
#define icon_height 32
-static char icon_bits[] = {
+static unsigned char icon_bits[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0xc0, 0x0c, 0x00,
0x00, 0x20, 0x10, 0x00, 0x00, 0x20, 0x30, 0x00, 0x00, 0x20, 0x30, 0x00,
0x00, 0x10, 0x20, 0x00, 0x00, 0x10, 0x60, 0x00, 0x00, 0x10, 0x67, 0x00,