diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e8faee87..55f98106 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,6 +10,7 @@ check:
         - vs2019
         - windows10
     script:
+        - git clean -xdf
         - cd Tools
         - pip install cmakelang
         - python format-cmake.py