diff --git a/src/luasocket/usocket.c b/src/luasocket/usocket.c
index 775e6fd..49e618c 100644
--- a/src/luasocket/usocket.c
+++ b/src/luasocket/usocket.c
@@ -426,7 +426,9 @@ const char *socket_gaistrerror(int err) {
         case EAI_MEMORY: return "memory allocation failure";
         case EAI_NONAME: 
             return "host or service not provided, or not known";
+#ifdef EAI_OVERFLOW
         case EAI_OVERFLOW: return "argument buffer overflow";
+#endif
 #ifdef EAI_PROTOCOL
         case EAI_PROTOCOL: return "resolved protocol is unknown";
 #endif