diff --git a/lib/sockunion.c b/lib/sockunion.c
index 039da1a..587b324 100644
--- a/lib/sockunion.c
+++ b/lib/sockunion.c
@@ -704,7 +704,7 @@
 int
 in6addr_cmp (struct in6_addr *addr1, struct in6_addr *addr2)
 {
-  int i;
+  unsigned int i;
   u_char *p1, *p2;
 
   p1 = (u_char *)addr1;