diff --git a/.gitlab/ci/gitlab.images.yml b/.gitlab/ci/gitlab.images.yml
index 72f9ade..639d5c6 100644
--- a/.gitlab/ci/gitlab.images.yml
+++ b/.gitlab/ci/gitlab.images.yml
@@ -33,7 +33,8 @@ gitlab push:
     GRAPHICSMAGICK: '1.3.36'
   parallel:
     matrix:
-      - RUBY: ['2.7', '3.0']
+      - DEBIAN: ['bullseye']
+        RUBY: ['2.7', '3.0']
         GIT: ['2.31', '2.33']
 
 gitlab-assets test: