diff --git a/.travis.yml b/.travis.yml
index 61be224..403e886 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,7 +21,7 @@ before_install:
 
 install:
   # Install test dependencies.
-  - pip install molecule yamllint ansible-lint docker
+  - pip install molecule[docker] yamllint ansible-lint docker
 
 before_script:
   # Use actual Ansible Galaxy role name for the project directory.