diff --git a/tox.ini b/tox.ini
index bf23320..e1ae8a1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,41 +1,42 @@
 [tox]
 envlist =
 	bashate,isort,jsonlint,flake8,py27
 skipsdist = True
 
 [testenv]
+basepython = python2.7
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/requirements-dev.txt
 commands = nosetests {posargs}
 whitelist_externals = bash
 
 [testenv:bashate]
 deps = bashate==0.5.1
 commands =
     bash -c "grep --recursive --binary-files=without-match \
         --files-with-match '^.!.*\(ba\)\?sh$' \
         --exclude-dir .tox \
         --exclude-dir .git \
         {toxinidir} | xargs bashate --error . --verbose"
 
 [testenv:isort]
 deps = isort==4.2.15
 commands =
     bash -c "find {toxinidir} \
         -type d \
             \( \
               -path {toxinidir}/.git -o \
               -path {toxinidir}/.tox -o \
               -path {toxinidir}/.venv \
             \) -prune -o \
         -name '*.py' \
         -print | xargs isort {posargs:--check-only} --verbose"
 
 [testenv:jsonlint]
 commands =
 	bash -c "set -euo pipefail && find conf/ -type f -name '*.json' | xargs -t -n1 python -m json.tool 2>&1 > /dev/null"
 
 [testenv:flake8]
 deps = flake8
 commands = flake8