diff --git a/tools/run_tests/run_xds_tests.py b/tools/run_tests/run_xds_tests.py
index d9291457872..84dedd379b7 100755
--- a/tools/run_tests/run_xds_tests.py
+++ b/tools/run_tests/run_xds_tests.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright 2020 gRPC authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");