diff --git a/slcan_attach.c b/slcan_attach.c
index 8410b65..7027666 100644
--- a/slcan_attach.c
+++ b/slcan_attach.c
@@ -88,7 +88,8 @@ int main(int argc, char **argv)
 	int send_read_status_flags = 0;
 	char *speed = NULL;
 	char *btr = NULL;
-	char buf[IFNAMSIZ+1];
+	char buf[20];
+	static struct ifreq ifr;
 	char *tty;
 	char *name = NULL;
 	int opt;
@@ -133,7 +134,7 @@ int main(int argc, char **argv)
 
 		case 'n':
 			name = optarg;
-			if (strlen(name) > IFNAMSIZ-1)
+			if (strlen(name) > sizeof(ifr.ifr_newname) - 1)
 				print_usage(argv[0]);
 			break;
 
@@ -201,16 +202,15 @@ int main(int argc, char **argv)
 		}
 
 		/* retrieve the name of the created CAN netdevice */
-		if (ioctl (fd, SIOCGIFNAME, buf) < 0) {
+		if (ioctl (fd, SIOCGIFNAME, ifr.ifr_name) < 0) {
 			perror("ioctl SIOCGIFNAME");
 			exit(1);
 		}
 
-		printf("attached tty %s to netdevice %s\n", tty, buf);
+		printf("attached tty %s to netdevice %s\n", tty, ifr.ifr_name);
 
 		/* try to rename the created device if requested */
 		if (name) {
-			struct ifreq ifr;
 			int s = socket(PF_INET, SOCK_DGRAM, 0);
  
 			printf("rename netdevice %s to %s ... ", buf, name);
@@ -218,8 +218,9 @@ int main(int argc, char **argv)
 			if (s < 0)
 				perror("socket for interface rename");
 			else {
-				strncpy (ifr.ifr_name, buf, IFNAMSIZ);
-				strncpy (ifr.ifr_newname, name, IFNAMSIZ);
+				/* current slcan%d name is still in ifr.ifr_name */
+				memset (ifr.ifr_newname, 0, sizeof(ifr.ifr_newname));
+				strncpy (ifr.ifr_newname, name, sizeof(ifr.ifr_newname) - 1);
  
 				if (ioctl(s, SIOCSIFNAME, &ifr) < 0)
 					printf("failed!\n");
diff --git a/slcand.c b/slcand.c
index 3c8c755..220048a 100644
--- a/slcand.c
+++ b/slcand.c
@@ -180,7 +180,8 @@ int main(int argc, char *argv[])
 	char *tty = NULL;
 	char const *devprefix = "/dev/";
 	char *name = NULL;
-	char buf[IFNAMSIZ+1];
+	char buf[20];
+	static struct ifreq ifr;
 	struct termios tios;
 	speed_t old_ispeed;
 	speed_t old_ospeed;
@@ -270,6 +271,8 @@ int main(int argc, char *argv[])
 		print_usage(argv[0]);
 
 	name = argv[optind + 1];
+	if (name && (strlen(name) > sizeof(ifr.ifr_newname) - 1))
+		print_usage(argv[0]);
 
 	/* Prepare the tty device name string */
 	pch = strstr(tty, devprefix);
@@ -369,23 +372,23 @@ int main(int argc, char *argv[])
 	}
 	
 	/* retrieve the name of the created CAN netdevice */
-	if (ioctl(fd, SIOCGIFNAME, buf) < 0) {
+	if (ioctl(fd, SIOCGIFNAME, ifr.ifr_name) < 0) {
 		perror("ioctl SIOCGIFNAME");
 		exit(EXIT_FAILURE);
 	}
 
-	syslogger(LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, buf);
+	syslogger(LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, ifr.ifr_name);
 	
 	/* try to rename the created netdevice */
 	if (name) {
-		struct ifreq ifr;
 		int s = socket(PF_INET, SOCK_DGRAM, 0);
 
 		if (s < 0)
 			perror("socket for interface rename");
 		else {
-			strncpy(ifr.ifr_name, buf, IFNAMSIZ);
-			strncpy(ifr.ifr_newname, name, IFNAMSIZ);
+			/* current slcan%d name is still in ifr.ifr_name */
+			memset (ifr.ifr_newname, 0, sizeof(ifr.ifr_newname));
+			strncpy (ifr.ifr_newname, name, sizeof(ifr.ifr_newname) - 1);
 
 			if (ioctl(s, SIOCSIFNAME, &ifr) < 0) {
 				syslogger(LOG_NOTICE, "netdevice %s rename to %s failed\n", buf, name);