1 files changed, 1 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index e64386f06..373d21b34 100644
--- a/configure.ac
+++ b/configure.ac
@@ -839,6 +839,7 @@ mips-sony-bsd|mips-sony-newsos4)
         if test "x$withval" != "xno" ; then
                 need_dash_r=1
         fi
+        CPPFLAGS="$CPPFLAGS -D_OPENBSD_SOURCE"
         AC_DEFINE([SSH_TUN_FREEBSD], [1], [Open tunnel devices the FreeBSD way])
         AC_CHECK_HEADER([net/if_tap.h], ,
             AC_DEFINE([SSH_TUN_NO_L2], [1], [No layer 2 tunnel support]))