diff --git a/mrbgems/mruby-socket/src/socket.c b/mrbgems/mruby-socket/src/socket.c
index b175d1964..c688d67f8 100644
--- a/mrbgems/mruby-socket/src/socket.c
+++ b/mrbgems/mruby-socket/src/socket.c
@@ -88,7 +88,7 @@ static int inet_pton(int af, const char *src, void *dst)
     return -1;
   }
 
-  for (struct addrinfo *r; r; r = r->ai_next) {
+  for (struct addrinfo *r = res; r; r = r->ai_next) {
     memcpy(dst, r->ai_addr, r->ai_addrlen);
   }