diff --git a/src/http_fetch.c b/src/http_fetch.c
index b3a5ea5..f2a74ba 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -1581,7 +1581,7 @@
 			       smp->data.u.str.data);
 			temp->area[smp->data.u.str.data] = '\0';
 			len = url2ipv4((char *) temp->area, &smp->data.u.ipv4);
-			if (len == smp->data.u.str.data) {
+			if (len > 0 && len == smp->data.u.str.data) {
 				/* plain IPv4 address */
 				smp->data.type = SMP_T_IPV4;
 				break;