diff --git a/src/libsec/port/x509.c b/src/libsec/port/x509.c
index 60b3d07..2bbf853 100644
--- a/src/libsec/port/x509.c
+++ b/src/libsec/port/x509.c
@@ -2077,8 +2077,7 @@
 	if(tag_decode(&p, pend, &tag, &isconstr) != ASN_OK ||
 	   tag.class != Universal || tag.num != SEQUENCE ||
 	   length_decode(&p, pend, &length) != ASN_OK ||
-	   p+length > pend ||
-	   p+length < p)
+	   length > pend - p)
 		return;
 	info = p;
 	if(ber_decode(&p, pend, &elem) != ASN_OK || elem.tag.num != SEQUENCE)