diff --git a/common.h b/common.h
index f928c44..e14946f 100644
--- a/common.h
+++ b/common.h
@@ -143,7 +143,7 @@ static inline int split_ip_netmask(int family,
 	char *tmp;
 	unsigned long ul;
 
-	int netmask_length;
+	int netmask_length, err;
 
 	/* IPv4 */
 	if (family == AF_INET)
@@ -159,10 +159,16 @@ static inline int split_ip_netmask(int family,
 	if (tmp != NULL) {
 		*tmp = '\0';
 		++tmp;
-		if (mystrtoul(&ul, tmp, netmask_length) == -ERANGE) {
+		err = mystrtoul(&ul, tmp, netmask_length);
+		if (err == -ERANGE) {
 			log_error("%s", "CIDR netmask out of range");
-			return -ERANGE;
+			return err;
 		}
+		if (err == -EINVAL) {
+			log_error("Error parsing %s as a number", tmp);
+			return err;
+		}
+
 		if (netmask != NULL)
 			*netmask = (uint8_t) ul;
 	}
diff --git a/vrrp_options.c b/vrrp_options.c
index 1e64074..76cdf68 100644
--- a/vrrp_options.c
+++ b/vrrp_options.c
@@ -70,7 +70,7 @@ static void vrrp_usage(void)
 int vrrp_options(struct vrrp *vrrp, struct vrrp_net *vnet, int argc,
 		 char *argv[])
 {
-	int optc;
+	int optc, err;
 	unsigned long opt;	/* strtoul */
 
 	static struct option const opts[] = {
@@ -97,12 +97,20 @@ int vrrp_options(struct vrrp *vrrp, struct vrrp_net *vnet, int argc,
 
 			/* vrid */
 		case 'v':
-			if ((mystrtoul(&opt, optarg, VRID_MAX) == -ERANGE)
-			    || (opt == 0)) {
+			err = mystrtoul(&opt, optarg, VRID_MAX);
+			if (err == -ERANGE || (err == 0 && opt == 0)) {
 				fprintf(stderr, "1 < vrid < 255\n");
 				vrrp_usage();
-				return -1;
+				return err;
 			}
+			if (err == -EINVAL) {
+				fprintf(stderr,
+					"Error parsing \"%s\" as a number\n",
+					optarg);
+				vrrp_usage();
+				return err;
+			}
+
 			vrrp->vrid = vnet->vrid = (uint8_t) opt;
 			break;
 
@@ -117,20 +125,38 @@ int vrrp_options(struct vrrp *vrrp, struct vrrp_net *vnet, int argc,
 
 			/* priority */
 		case 'p':
-			if (mystrtoul(&opt, optarg, VRRP_PRIO_MAX) == -ERANGE) {
+			err = mystrtoul(&opt, optarg, VRRP_PRIO_MAX);
+			if (err == -ERANGE) {
 				fprintf(stderr, "0 < priority < 255\n");
 				vrrp_usage();
 				return -1;
 			}
+			if (err == -EINVAL) {
+				fprintf(stderr,
+					"Error parsing \"%s\" as a number\n",
+					optarg);
+				vrrp_usage();
+				return err;
+			}
+
 			vrrp->priority = (uint8_t) opt;
 			break;
 
 			/* delay */
 		case 't':
-			if (mystrtoul(&opt, optarg, ADVINT_MAX) == -ERANGE) {
+			err = mystrtoul(&opt, optarg, ADVINT_MAX);
+			if (err == -ERANGE) {
 				vrrp_usage();
 				return -1;
 			}
+			if (err == -EINVAL) {
+				fprintf(stderr,
+					"Error parsing \"%s\" as a number\n",
+					optarg);
+				vrrp_usage();
+				return err;
+			}
+
 			vrrp->adv_int = (uint16_t) opt;
 			break;
 
@@ -150,12 +176,20 @@ int vrrp_options(struct vrrp *vrrp, struct vrrp_net *vnet, int argc,
 
 			/* RFC - version */
 		case 'r':
-			if ((mystrtoul(&opt, optarg, RFC5798) == -ERANGE)
-			    || (opt < RFC3768)) {
-				fprintf(stderr, "Version 2 or 3 : %ld\n", opt);
+			err = mystrtoul(&opt, optarg, RFC5798);
+			if (err == -ERANGE || (err == 0 && opt < RFC3768)) {
+				fprintf(stderr, "Version 2 or 3 : %s\n", optarg);
 				vrrp_usage();
 				return -1;
 			}
+			if (err == -EINVAL) {
+				fprintf(stderr,
+					"Error parsing \"%s\" as a number\n",
+					optarg);
+				vrrp_usage();
+				return err;
+			}
+
 			vrrp->version = (uint8_t) opt;
 			break;