--- a/src/flagset.c
+++ b/src/flagset.c
@@ -134,7 +134,7 @@
 
 int netcat_flag_count(void)
 {
-  register char c;
+  register unsigned char c;
   register int i;
   int ret = 0;
 
@@ -154,8 +154,8 @@
 	Assumed that the bit number 1 is the sign, and that we will shift the
 	bit 1 (or the bit that takes its place later) until the the most right,
 	WHY it has to keep the wrong sign? */
-      ret -= (c >> 7);
-      c <<= 1;
+      ret += (c & 1);
+      c >>= 1;
     }
   }