--- a/src/sniffd/autoconfig.c
+++ b/src/sniffd/autoconfig.c
@@ -68,7 +68,7 @@
   struct ifreq ifr;
 
   strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
-  ifr.ifr_name[IFNAMSIZ] = '\0';
+  ifr.ifr_name[IFNAMSIZ -1] = '\0';
   if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0){
     return (-1);
   }
@@ -89,7 +89,7 @@
   struct ifreq ifr;
 
   strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
-  ifr.ifr_name[IFNAMSIZ] = '\0';
+  ifr.ifr_name[IFNAMSIZ -1] = '\0';
   if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0){
     return (-1);
   }
@@ -129,7 +129,7 @@
 {
   /* Set device name */
   strncpy(pwrq->ifr_name, ifname, IFNAMSIZ);
-  pwrq->ifr_name[IFNAMSIZ] = '\0';
+  pwrq->ifr_name[IFNAMSIZ -1] = '\0';
   
   /* Do the request */
   return(ioctl(skfd, request, pwrq));