Index: openvpn/tun.c
===================================================================
--- openvpn/tun.c	(revision 2677)
+++ openvpn/tun.c	(revision 2679)
@@ -1221,17 +1221,20 @@
   if (tt)
     {
 #ifdef CONFIG_FEATURE_IPROUTE
-	char command_line[256];
-	/*
-	 * Flush IP configuration for the device
-	 */
-	openvpn_snprintf (command_line, sizeof (command_line),
+	if (tt->type != DEV_TYPE_NULL)
+	  {
+	    char command_line[256];
+	    /*
+	     * Flush IP configuration for the device
+	     */
+	    openvpn_snprintf (command_line, sizeof (command_line),
 			  "%s addr flush dev %s",
 			  iproute_path,
 			  tt->actual_name
 			  );
-	msg (M_INFO, "%s", command_line);
-	system_check (command_line, NULL, S_FATAL, "Linux ip flush failed");
+	    msg (M_INFO, "%s", command_line);
+	    system_check (command_line, NULL, S_FATAL, "Linux ip flush failed");
+	  }
 #endif
       close_tun_generic (tt);
       free (tt);