diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c
index 0d86fe54bb0..f5271c6d5a3 100644
--- a/lib/libc/net/getaddrinfo.c
+++ b/lib/libc/net/getaddrinfo.c
@@ -949,7 +949,7 @@ matchlen(struct sockaddr *src, struct sockaddr *dst)
 
 	while (s < lim)
 		if ((r = (*d++ ^ *s++)) != 0) {
-			while (r < addrlen * 8) {
+			while ((r & 0x80) == 0) {
 				match++;
 				r <<= 1;
 			}
diff --git a/lib/libc/net/name6.c b/lib/libc/net/name6.c
index 7e52a515019..b0970786dd8 100644
--- a/lib/libc/net/name6.c
+++ b/lib/libc/net/name6.c
@@ -930,7 +930,7 @@ matchlen(struct sockaddr *src, struct sockaddr *dst)
 
 	while (s < lim)
 		if ((r = (*d++ ^ *s++)) != 0) {
-			while (r < addrlen * 8) {
+			while ((r & 0x80) == 0) {
 				match++;
 				r <<= 1;
 			}