diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 04e955245420848112bde32006da58ba45903209..68fc88e0162fcb1847f10043231059650cafd344 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -17,6 +17,8 @@ prepare:index:
   rules:
     - if: $CI_COMMIT_REF_NAME
     - if: '$CI_PIPELINE_SOURCE == "merge_request_event" && $CI_COMMIT_MESSAGE !~ /tmpBranch/ && $CI_COMMIT_MESSAGE !~ /Update index/'
+  before_script:
+    - pip install natsort
   script:
     - python .ci/generateIndex.py
     - mkdir .tmp