diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6ee2a60e5..66a87d1d0 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -10,7 +10,7 @@ jobs:
         command: brew update > /dev/null && brew upgrade python
     - run:
         name: install tox
-        command: sudo pip install --upgrade tox==2.1.1
+        command: sudo pip3 install --upgrade tox==2.1.1
     - run:
         name: unit tests
         command: tox -e py27,py36 -- tests/unit