diff --git a/.travis.yml b/.travis.yml
index 4685245..2b2ca7b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,7 +36,7 @@ script:
   - "ansible-playbook main.yml --syntax-check"
 
   # Test the playbook.
-  - 'travis_wait 30 ansible-playbook --extra-vars "configure_sudoers: False" main.yml'
+  - "travis_wait 30 ansible-playbook --extra-vars '{\"configure_sudoers\":\"false\"}' main.yml"
 
   # Test the playbook's idempotence.
   - idempotence=$(mktemp)