From 9fb17b3ca7b9360c1c32d45b180591a3220f9758 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 20 Jun 2016 10:19:56 +0200
Subject: [PATCH] use c99

---
 configure.ac | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure.ac b/configure.ac
index 65926453b..494877381 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,6 +32,7 @@ LT_INIT
 
 # Checks for programs.
 AC_PROG_CC
+AC_PROG_CC_C99
 
 CFLAGS="-Wall $CFLAGS"