--- configure.ac.orig	2014-05-03 17:24:26.000000000 +0900
+++ configure.ac	2014-05-03 17:41:18.000000000 +0900
@@ -224,6 +224,7 @@
 #include <netinet/tcp.h>
 ])
 
+ac_use_keepalives=no
 use_keepalives=no
 if test x$ac_use_keepalives != xno; then
 	use_keepalives=yes