diff --git a/smoke/venv.sh b/smoke/venv.sh
index 3527657..58bb1a5 100755
--- a/smoke/venv.sh
+++ b/smoke/venv.sh
@@ -2,7 +2,7 @@
 
 # set python version
 VERSION=${VERSION:-3.7}
-PYTHON=python$VERSION
+PYTHON=${PYTHON:-python$VERSION}
 METHOD=${METHOD:-venv}
 TOX=${TOX:-true}
 
@@ -82,4 +82,8 @@ deps = pytest
 commands = python -m pytest -v test_foo.py
 EOF
 
-tox -e py${VERSION/./}
+if [[ $PYTHON == python* ]]; then
+    tox -e py${VERSION/./}
+else
+    tox -e $PYTHON
+fi