diff --git a/ChangeLog b/ChangeLog
index 60a36d18..8c6685a3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-02-12  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Added a check to see struct sockaddr_in has sin_len member.
+	* configure.ac
+	
 2009-02-12  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Fixed buffer overrun.
diff --git a/config.h.in b/config.h.in
index 31a44953..37937a1f 100644
--- a/config.h.in
+++ b/config.h.in
@@ -322,6 +322,9 @@
 /* Define to 1 if you have the `snprintf' function. */
 #undef HAVE_SNPRINTF
 
+/* Define to 1 if struct sockaddr has sin_len member. */
+#undef HAVE_SOCKADDR_SIN_LEN
+
 /* Define to 1 if you have the `socket' function. */
 #undef HAVE_SOCKET
 
diff --git a/configure b/configure
index a23bdb21..5a2bb4f4 100755
--- a/configure
+++ b/configure
@@ -22003,6 +22003,110 @@ fi
     ;;
 esac
 
+{ echo "$as_me:$LINENO: checking for struct sockaddr_in.sin_len" >&5
+echo $ECHO_N "checking for struct sockaddr_in.sin_len... $ECHO_C" >&6; }
+if test "${ac_cv_member_struct_sockaddr_in_sin_len+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <netinet/in.h>
+
+int
+main ()
+{
+static struct sockaddr_in ac_aggr;
+if (ac_aggr.sin_len)
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_cxx_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then
+  ac_cv_member_struct_sockaddr_in_sin_len=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <netinet/in.h>
+
+int
+main ()
+{
+static struct sockaddr_in ac_aggr;
+if (sizeof ac_aggr.sin_len)
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_cxx_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then
+  ac_cv_member_struct_sockaddr_in_sin_len=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_cv_member_struct_sockaddr_in_sin_len=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_member_struct_sockaddr_in_sin_len" >&5
+echo "${ECHO_T}$ac_cv_member_struct_sockaddr_in_sin_len" >&6; }
+if test $ac_cv_member_struct_sockaddr_in_sin_len = yes; then
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_SOCKADDR_SIN_LEN 1
+_ACEOF
+
+fi
+
+
 ac_config_files="$ac_config_files Makefile src/Makefile test/Makefile po/Makefile.in m4/Makefile intl/Makefile lib/Makefile doc/Makefile"
 
 cat >confcache <<\_ACEOF
diff --git a/configure.ac b/configure.ac
index 6f4ed2d6..772fa131 100644
--- a/configure.ac
+++ b/configure.ac
@@ -329,6 +329,12 @@ case "$target" in
     ;;
 esac
 
+AC_CHECK_MEMBER([struct sockaddr_in.sin_len],
+                [AC_DEFINE([HAVE_SOCKADDR_SIN_LEN],[1],
+                  [Define to 1 if struct sockaddr has sin_len member.])],
+                [],
+                [[#include <netinet/in.h>]])
+
 AC_CONFIG_FILES([Makefile
 		src/Makefile
 		test/Makefile