diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ea83829bcf623df766a2e3a3d0533f2c6c49f854..e77b7dd17d535500fec44102866c421cfc9030a4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -153,17 +153,6 @@ build-2204:
     paths:
       - build
 
-build-release-2204:
-  # .prepare should be last, since it overwrites "image:".
-  extends: [".needs-base-2204",".prepare"]
-  stage: build
-  variables:
-    DOCKER_IMAGE: ${CI_REGISTRY_IMAGE}/dp3:${CI_COMMIT_SHORT_SHA}
-    DOCKER_FILE: ./docker/ubuntu_20_04_dp3
-    DOCKER_BUILD_ARG: --build-arg BASE_TAG=$BASE_IMAGE_2204
-  rules: # This job should always overwrite the rules: from .prepare!
-    - if: '$CI_COMMIT_BRANCH == "master"'
-
 build-doc-2204:
   stage: build
   extends: [".failable",".needs-base-2204"]
diff --git a/README.md b/README.md
index e29c6fb7b28e5718dc08f49782c4eaa8f7f528d8..890448cd35b33195456d791fe73e3522b7468c92 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ The DP3 documentation can be found at: https://dp3.readthedocs.org
 This repository is a continuation of the one at svn.astron.nl/LOFAR. In particular, it has branched off at LOFAR Release 3.2 (Sept 2018). The version of DP3 that is in the ASTRON repository is no longer maintained.
 
 ## Installation
-Some non-standard dependencies of this project are: armadillo, boost, boost-python, casacore, hdf5, aoflagger, and EveryBeam. See the Dockerfiles [`docker/ubuntu_20_04_base`](docker/ubuntu_20_04_base) and [`docker/ubuntu_20_04_dp3`](docker/ubuntu_20_04_dp3) as examples.
+Some non-standard dependencies of this project are: armadillo, boost, boost-python, casacore, hdf5, aoflagger, and EveryBeam. See the Dockerfiles [`docker/ubuntu_20_04_base`](docker/ubuntu_20_04_base) and/or [`docker/ubuntu_22_04_base`](docker/ubuntu_22_04_base) as examples.
 
 Typical installation commands:
 ```
diff --git a/docker/ubuntu_20_04_dp3 b/docker/ubuntu_20_04_dp3
deleted file mode 100644
index 32ad630c6d8158298f592cbef6728c735aa8658b..0000000000000000000000000000000000000000
--- a/docker/ubuntu_20_04_dp3
+++ /dev/null
@@ -1,12 +0,0 @@
-ARG BASE_TAG=latest
-FROM $BASE_TAG
-
-ADD . /src
-
-# Build DP3
-RUN mkdir /build && cd /build \
-    && cmake ../src \
-    && make -j$(($(nproc) / 2 > 0 ? $(nproc) / 2:1)) \
-    && make install -j$(($(nproc) / 2 > 0 ? $(nproc) / 2:1)) \
-    && DP3 \
-    && rm -r /src /build