diff --git a/tox.ini b/tox.ini
index 3888605..8ef76a6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,6 +20,7 @@
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 setenv =
    {[testenv]setenv}
    PYTHON=coverage run --source tempest_horizon --parallel-mode