diff --git a/cangw.c b/cangw.c
index bf45331..6369a9f 100644
--- a/cangw.c
+++ b/cangw.c
@@ -743,10 +743,18 @@ int main(int argc, char **argv)
 
 		case 's':
 			src_ifindex = if_nametoindex(optarg);
+			if (!src_ifindex) {
+				perror("src if_nametoindex");
+				exit(1);
+			}
 			break;
 
 		case 'd':
 			dst_ifindex = if_nametoindex(optarg);
+			if (!dst_ifindex) {
+				perror("dst if_nametoindex");
+				exit(1);
+			}
 			break;
 
 		case 'X':
diff --git a/cansniffer.c b/cansniffer.c
index 4e9d47d..4089431 100644
--- a/cansniffer.c
+++ b/cansniffer.c
@@ -332,14 +332,19 @@ int main(int argc, char **argv)
 	}
 
 	addr.can_family = AF_CAN;
+	addr.can_ifindex = 0; /* 'any' CAN interface */
 
-	if (strcmp(ANYDEV, argv[optind]) != 0)
+	/* check for specific CAN interface */
+	if (strcmp(ANYDEV, argv[optind]) != 0) {
 		addr.can_ifindex = if_nametoindex(argv[optind]);
-	else
-		addr.can_ifindex = 0; /* any can interface */
+		if (!addr.can_ifindex) {
+			perror("if_nametoindex");
+			return 1;
+		}
+	}
 
 	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
-		perror("connect");
+		perror("bind");
 		return 1;
 	}
 
diff --git a/isotpdump.c b/isotpdump.c
index 6869cc6..4e2dbaf 100644
--- a/isotpdump.c
+++ b/isotpdump.c
@@ -325,6 +325,10 @@ int main(int argc, char **argv)
 
 	addr.can_family = AF_CAN;
 	addr.can_ifindex = if_nametoindex(argv[optind]);
+	if (!addr.can_ifindex) {
+		perror("if_nametoindex");
+		return 1;
+	}
 
 	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 		perror("bind");
diff --git a/isotpperf.c b/isotpperf.c
index 97bf4cf..6252ac9 100644
--- a/isotpperf.c
+++ b/isotpperf.c
@@ -189,6 +189,10 @@ int main(int argc, char **argv)
 
 	addr.can_family = AF_CAN;
 	addr.can_ifindex = if_nametoindex(argv[optind]);
+	if (!addr.can_ifindex) {
+		perror("if_nametoindex");
+		return 1;
+	}
 
 	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 		perror("bind");
diff --git a/isotprecv.c b/isotprecv.c
index 406cf5d..4b41022 100644
--- a/isotprecv.c
+++ b/isotprecv.c
@@ -234,6 +234,10 @@ int main(int argc, char **argv)
 
     addr.can_family = AF_CAN;
     addr.can_ifindex = if_nametoindex(argv[optind]);
+    if (!addr.can_ifindex) {
+	perror("if_nametoindex");
+	exit(1);
+    }
 
     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 	perror("bind");
diff --git a/isotpsend.c b/isotpsend.c
index 3ea574c..6fe1b99 100644
--- a/isotpsend.c
+++ b/isotpsend.c
@@ -237,6 +237,10 @@ int main(int argc, char **argv)
 
     addr.can_family = AF_CAN;
     addr.can_ifindex = if_nametoindex(argv[optind]);
+    if (!addr.can_ifindex) {
+	perror("if_nametoindex");
+	exit(1);
+    }
 
     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 	perror("bind");
diff --git a/isotpserver.c b/isotpserver.c
index ed61bb2..5c161d7 100644
--- a/isotpserver.c
+++ b/isotpserver.c
@@ -350,6 +350,10 @@ int main(int argc, char **argv)
 
 	caddr.can_family = AF_CAN;
 	caddr.can_ifindex = if_nametoindex(argv[optind]);
+	if (!caddr.can_ifindex) {
+		perror("if_nametoindex");
+		exit(1);
+	}
 
 	if (bind(sc, (struct sockaddr *)&caddr, caddrlen) < 0) {
 		perror("bind");
diff --git a/isotpsniffer.c b/isotpsniffer.c
index a06ecef..bdd8211 100644
--- a/isotpsniffer.c
+++ b/isotpsniffer.c
@@ -296,6 +296,11 @@ int main(int argc, char **argv)
 
 	addr.can_family = AF_CAN;
 	addr.can_ifindex = if_nametoindex(if_name);
+	if (!addr.can_ifindex) {
+		perror("if_nametoindex");
+		r = 1;
+		goto out;
+	}
 
 	setsockopt(s, SOL_CAN_ISOTP, CAN_ISOTP_OPTS, &opts, sizeof(opts));
 
diff --git a/slcanpty.c b/slcanpty.c
index d233c0d..e6f1efe 100644
--- a/slcanpty.c
+++ b/slcanpty.c
@@ -501,6 +501,10 @@ int main(int argc, char **argv)
 
 	addr.can_family = AF_CAN;
 	addr.can_ifindex = if_nametoindex(argv[2]);
+	if (!addr.can_ifindex) {
+		perror("if_nametoindex");
+		return 1;
+	}
 
 	/* disable reception of CAN frames until we are opened by 'O' */
 	setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);