diff --git a/acconfig.h b/acconfig.h
index 616cc069a..87e1d7cc3 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -10,3 +10,8 @@
 /* Define cpu-machine-OS */
 #undef OS
 
+/* Number of arguments your gethostbyaddr_r() function accepts */
+#undef GETHOSTBYADDR_R_NARGS
+
+/* Number of arguments your gethostbyname_r() function accepts */
+#undef GETHOSTBYNAME_R_NARGS