/usr/bin/env python -> /usr/bin/env python2.7
diff --git a/tools/run_tests/run_stress_tests.py b/tools/run_tests/run_stress_tests.py
index 193ff2e..d1faf7d 100755
--- a/tools/run_tests/run_stress_tests.py
+++ b/tools/run_tests/run_stress_tests.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2.7
 # Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #