diff --git a/.circleci/config.yml b/.circleci/config.yml
index 26a827bc..502464e0 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -42,7 +42,7 @@ jobs:
     # This is based on your 1.0 configuration file or project settings
     - run:
         working_directory: ~/rocky/python-uncompyle6
-        command: pyenv install 2.7.13 && pyenv local 2.7.13 && pyenv rehash && pip install virtualenv && pip install nose && pip install pep8 && pyenv rehash
+        command: pyenv install 2.7.13 && pyenv local 2.7.13 && pyenv rehash && pip install virtualenv && pip install nose && pip install pep8 && pip install six && pyenv rehash
     # Dependencies
     #   This would typically go in either a build or a build-and-test job when using workflows
     # Restore the dependency cache