diff --git a/Modules/getaddrinfo.c b/Modules/getaddrinfo.c
index b6fb53c..a61749d 100644
--- a/Modules/getaddrinfo.c
+++ b/Modules/getaddrinfo.c
@@ -334,12 +334,17 @@ getaddrinfo(const char*hostname, const char*servname,
      */
     if (servname) {
         if (str_isnumber(servname)) {
+            u_long servnum;
+
             if (pai->ai_socktype == GAI_ANY) {
                 /* caller accept *GAI_ANY* socktype */
                 pai->ai_socktype = SOCK_DGRAM;
                 pai->ai_protocol = IPPROTO_UDP;
             }
-            port = htons((u_short)atoi(servname));
+            servnum = strtoul(servname, NULL, 10);
+            if (servnum > 65535)
+                ERR(EAI_SERVICE);
+            port = htons((u_short)servnum);
         } else {
             struct servent *sp;
             char *proto;