diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 6b7c8ef1..60a3a179 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -281,7 +281,6 @@ out:
 static bool
 do_set_mtu_service(const struct tuntap *tt, const short family, const int mtu)
 {
-    DWORD len;
     bool ret = false;
     ack_message_t ack;
     struct gc_arena gc = gc_new();