diff --git a/tools/test/topos/attcli.py b/tools/test/topos/attcli.py
index 1945320..80bac6f 100644
--- a/tools/test/topos/attcli.py
+++ b/tools/test/topos/attcli.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 """
 CLI for test with AttMplsTopo