diff --git a/.travis.yml b/.travis.yml
index bac98bb4..8d764a32 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -33,7 +33,7 @@ install:
 - travis_retry pip install coveralls
 - travis_retry pip install flake8
 - travis_retry pip install tox>=1.9
-- travis_retry pip install virtualenv<14.0.0  # virtualenv>=14.0.0 has dropped Python 3.2 support (and pypy3 is based on py32)
+- travis_retry pip install "virtualenv<14.0.0"  # virtualenv>=14.0.0 has dropped Python 3.2 support (and pypy3 is based on py32)
 - travis_retry tox -e $(echo py$TRAVIS_PYTHON_VERSION-mg$PYMONGO | tr -d . | sed -e 's/pypypy/pypy/') -- -e test
 
 # Run flake8 for py27