diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8a4179c4a031c4c2fa3dc8a5b51dd34c86999abd..6cfedb5aed606cc1fb31a3c584a66e3c52c566e7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -54,7 +54,7 @@ bookworm:
     - linux
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/bookworm-prebuild:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/bookworm-prebuild:latest
   needs:
     - codespell
   script:
@@ -70,7 +70,7 @@ makefile:
     - linux
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/bookworm-prebuild:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/bookworm-prebuild:latest
   needs:
     - codespell
   script:
@@ -89,7 +89,7 @@ all_commits:
   # Test each commit up to main, to facilitate bisecting.
   stage: test
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
   needs: ["rust-stable"]
   script:
     - apt update && apt install -y libbotan-2-dev
@@ -104,7 +104,7 @@ codespell:
     - linux
   stage: pre-check
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/bookworm:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/bookworm:latest
 
   before_script:
     - *before_script_start
@@ -119,7 +119,7 @@ rust-stable:
     - linux
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
   before_script:
     - *before_script_start
     - rustup override set stable
@@ -136,7 +136,7 @@ rust-stable-armv7:
     - linux
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/bullseye-cross-arm-prebuild:latest
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/bullseye-cross-arm-prebuild:latest
   before_script:
     - *before_script_start
     - cat .ci/snippet_for_cross_compilation_config.toml >> .cargo/config.toml
@@ -157,7 +157,7 @@ windows-gnu-cng:
     - win2019
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/windows-gnu
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/windows-gnu
   before_script:
     # the default before_scipt scriptlet doesn't work on Powershell
     - rustup default "1.63.0"
@@ -179,7 +179,7 @@ windows-msvc-cng:
     - win2019
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/windows-msvc
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/windows-msvc
   before_script:
     # We don't call *before_script_start or *before_script_end as we
     # don't have bash, clang, etc.
@@ -199,7 +199,7 @@ windows-msvc-nmakefile:
     - win2019
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/windows-msvc
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/windows-msvc
   before_script:
     # We don't call *before_script_start or *before_script_end as we
     # don't have bash, clang, etc.
@@ -219,7 +219,7 @@ windows-msvc-msbuild:
     - win2019
   stage: build
   interruptible: true
-  image: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/windows-msvc
+  image: 192.168.122.1:5000/sequoia-pgp/build-docker-image/windows-msvc
   before_script:
     # We don't call *before_script_start or *before_script_end as we
     # don't have bash, clang, etc.
@@ -243,7 +243,7 @@ windows-msvc32-cng:
   stage: build
   interruptible: true
   image:
-    name: $CONTAINER_REGISTRY/sequoia-pgp/build-docker-image/windows-msvc
+    name: 192.168.122.1:5000/sequoia-pgp/build-docker-image/windows-msvc
     # Set up a cross compilation environment for building x86 binaries on amd64, line copied from Dockerfile.windows.msvc
     # see https://renenyffenegger.ch/notes/Windows/dirs/Program-Files-x86/Microsoft-Visual-Studio/version/edition/Common7/Tools/VsDevCmd_bat
     #