diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b0806ba8d759a1228bee81c0115d3300d8346ad5..aeec961daee6c1017d6c705fdc8d4d3279883f93 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,11 +15,6 @@ before_script:
   script:
     - /kaniko/executor --context $CI_PROJECT_DIR/$IMAGE_NAME --dockerfile $IMAGE_NAME/Dockerfile --build-arg DEBIAN_RELEASE=$DEBIAN_RELEASE --destination $CI_REGISTRY_IMAGE/$IMAGE_NAME:$DEBIAN_RELEASE-$CI_COMMIT_SHA --destination $CI_REGISTRY_IMAGE/$IMAGE_NAME:$DEBIAN_RELEASE
 
-.build-stretch:
-  extends: .build
-  variables:
-    DEBIAN_RELEASE: stretch
-
 .build-buster:
   extends: .build
   variables:
@@ -30,12 +25,6 @@ before_script:
   variables:
     DEBIAN_RELEASE: bullseye
 
-base-stretch:
-  extends: .build-stretch
-  stage: base
-  variables:
-    IMAGE_NAME: fsmpi-base
-
 base-buster:
   extends: .build-buster
   stage: base
@@ -60,12 +49,6 @@ latex-bullseye:
   variables:
     IMAGE_NAME: fsmpi-latex
 
-packages-stretch:
-  extends: .build-stretch
-  stage: first
-  variables:
-    IMAGE_NAME: fsmpi-packages
-
 packages-buster:
   extends: .build-buster
   stage: first
@@ -78,12 +61,6 @@ packages-bullseye:
   variables:
     IMAGE_NAME: fsmpi-packages
 
-python-stretch:
-  extends: .build-stretch
-  stage: first
-  variables:
-    IMAGE_NAME: fsmpi-python
-
 python-buster:
   extends: .build-buster
   stage: first
@@ -108,12 +85,6 @@ ansible-bullseye:
   variables:
     IMAGE_NAME: fsmpi-ansible
 
-website-stretch:
-  extends: .build-stretch
-  stage: second
-  variables:
-    IMAGE_NAME: fsmpi-website
-
 website-buster:
   extends: .build-buster
   stage: second
diff --git a/fsmpi-base/Dockerfile b/fsmpi-base/Dockerfile
index bd26835da70849f06fe122597ecf4f197050b31c..1c4f4f691369c4aff63d3a0b0db54bc79cc13484 100644
--- a/fsmpi-base/Dockerfile
+++ b/fsmpi-base/Dockerfile
@@ -1,4 +1,4 @@
-ARG DEBIAN_RELEASE=stretch
+ARG DEBIAN_RELEASE=bullseye
 FROM debian:${DEBIAN_RELEASE}
 ARG DEBIAN_RELEASE
 ENV LANG C.UTF-8
diff --git a/fsmpi-base/stretch.list b/fsmpi-base/stretch.list
deleted file mode 100644
index a7c52cb09ea5bbe34b13289ebd9823017be7becc..0000000000000000000000000000000000000000
--- a/fsmpi-base/stretch.list
+++ /dev/null
@@ -1,3 +0,0 @@
-deb http://ftp.halifax.rwth-aachen.de/debian stretch main
-deb http://security.debian.org/debian-security stretch/updates main
-deb http://ftp.halifax.rwth-aachen.de/debian stretch-updates main
diff --git a/fsmpi-packages/Dockerfile b/fsmpi-packages/Dockerfile
index 964b9e9d7eaf2e3a4304cf9e175a0236e59f0021..d8da4e7200489151f6e8c130101d16d679cd713f 100644
--- a/fsmpi-packages/Dockerfile
+++ b/fsmpi-packages/Dockerfile
@@ -1,3 +1,3 @@
-ARG DEBIAN_RELEASE=stretch
+ARG DEBIAN_RELEASE=bullseye
 FROM registry.git.fsmpi.rwth-aachen.de/infra/ci-containers/fsmpi-base:${DEBIAN_RELEASE}
 RUN apt-get update && apt-get install -y build-essential dpkg-dev quilt devscripts git curl && rm -rf /var/lib/apt/lists/*
diff --git a/fsmpi-python/Dockerfile b/fsmpi-python/Dockerfile
index 04e0fd35896cb74ae2ac8ad122c28cf66249a22a..fd751884857686ee72ee32203342621f248f320a 100644
--- a/fsmpi-python/Dockerfile
+++ b/fsmpi-python/Dockerfile
@@ -1,3 +1,3 @@
-ARG DEBIAN_RELEASE=stretch
+ARG DEBIAN_RELEASE=bullseye
 FROM registry.git.fsmpi.rwth-aachen.de/infra/ci-containers/fsmpi-base:${DEBIAN_RELEASE}
 RUN apt-get update && apt-get install -y python3 python3-pip python3-venv flake8 curl && rm -rf /var/lib/apt/lists/*
diff --git a/fsmpi-website/Dockerfile b/fsmpi-website/Dockerfile
index c3fb0156deb8323a72bccdb7df574ba49abc85a0..b17178ca4786f388bade1e3db3892bb0c215e013 100644
--- a/fsmpi-website/Dockerfile
+++ b/fsmpi-website/Dockerfile
@@ -1,3 +1,3 @@
-ARG DEBIAN_RELEASE=stretch
+ARG DEBIAN_RELEASE=bullseye
 FROM registry.git.fsmpi.rwth-aachen.de/infra/ci-containers/fsmpi-python:${DEBIAN_RELEASE}
 RUN apt-get update && apt-get install -y openssh-client rsync default-jre git && rm -rf /var/lib/apt/lists/*