diff --git a/.travis.yml b/.travis.yml
index 83288a423cb76ab297b8501b63961bce762bec45..b6210b447de3f9a7423415c418900c2424616504 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -116,7 +116,7 @@ jobs:
       env: Codecov
       before_script:
         - composer update
-        - php vendor/bin/phpunit
+        - XDEBUG_MODE=coverage php vendor/bin/phpunit
       script:
         - bash <(curl -s https://codecov.io/bash)