diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 868dc67ac74d5155f0cfdc50ed86ac160a13c110..4311743f8eae16cac93da01c27c6313f24803938 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,11 +1,11 @@
 image: ruby
 
 before_script:
-  - gem install bundler:2.3
+  - gem install bundler:2.3.26
 
 pages:
   script:
-    - bundle _2.3_ install
+    - bundle _2.3.26_ install
     - bundle exec jekyll build -d public
   tags:
     - docker