diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e408b11..7eae1c3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -14,6 +14,8 @@ test:php:
     paths:
       - build/
       - vendor/
+  variables:
+    COMPOSER_ROOT_VERSION: dev-master
   before_script:
     - composer update
   script: