diff --git a/.travis.yml b/.travis.yml
index 61180db..85540ec 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,6 +29,6 @@ jobs:
 cache: pip
 
 install:
-- pip install tox
+- pip install tox tox-venv
 
 script: tox
diff --git a/appveyor.yml b/appveyor.yml
index 0a8ce5c..3d55a92 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -15,7 +15,7 @@ install:
 build: off
 
 test_script:
-  - "python -m pip install tox"
+  - "python -m pip install tox tox-venv"
   - "tox"
 
 version: '{build}'