diff --git a/tox.ini b/tox.ini
index 755ce750..e1c739d2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,19 +18,23 @@ whitelist_externals =
   find
 
 [testenv:pep8]
+basepython = python3
 commands = flake8 {posargs}
 
 [testenv:genconfig]
+basepython = python3
 commands =
     oslo-config-generator --config-file tools/config/config-generator.qinling.conf \
     --output-file etc/qinling.conf.sample
 
 #set PYTHONHASHSEED=0 to prevent oslo_policy.sphinxext from randomly failing.
 [testenv:venv]
+basepython = python3
 setenv = PYTHONHASHSEED=0
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 setenv =
     {[testenv]setenv}
     PYTHON=coverage run --source qinling --parallel-mode
@@ -38,6 +42,7 @@ commands =
     {toxinidir}/tools/cover.sh {posargs}
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 whitelist_externals = rm
 commands =
@@ -45,11 +50,13 @@ commands =
   sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [flake8]