diff --git a/.travis.yml b/.travis.yml
index c8b09ff..a3fd73f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,6 +16,7 @@ install:
   - source ~/.nvm/nvm.sh && nvm install --lts
 
 before_script:
+  - rm composer.lock
   - composer install -n
   - npm install -g mocha
   - cd js && npm install