diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index edfa0d13ca13466b0054aed6e2b445803ecd8a40..9d1094ba047c9d682ce6fc31d6b0406b6b7cd897 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -3,6 +3,13 @@
 before_script:
   - duneci-install-module https://git.imp.fu-berlin.de/agnumpde/dune-matrix-vector.git
 
+dune:2.9 debian-11 gcc-10 C++20:
+  variables:
+    DUNECI_BRANCH: releases/2.9
+  image: registry.dune-project.org/docker/ci/dune:2.9-debian-11-gcc-10-20
+  before_script:
+  script: duneci-standard-test
+
 dune:git ubuntu-20-04 clang-10  C++17:
   image: registry.dune-project.org/docker/ci/dune:git-ubuntu-20.04-clang-10-17
   script: duneci-standard-test