diff --git a/src/tun.c b/src/tun.c
index 772f789..df2297e 100644
--- a/src/tun.c
+++ b/src/tun.c
@@ -115,6 +115,7 @@ open_tun(const char *tun_device)
 
 		warn("open_tun: Couldn't set interface name");
 	}
+	warn("error when opening tun");
 	return -1;
 }