diff --git a/images/magnum/Dockerfile b/images/magnum/Dockerfile
index eca883d..6abfca0 100644
--- a/images/magnum/Dockerfile
+++ b/images/magnum/Dockerfile
@@ -12,7 +12,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-FROM registry.atmosphere.dev/library/ubuntu:main AS helm
+ARG RELEASE
+
+FROM registry.atmosphere.dev/library/ubuntu:${RELEASE} AS helm
 ARG TARGETOS
 ARG TARGETARCH
 ARG HELM_VERSION=3.14.0
@@ -20,7 +22,7 @@
 RUN tar -xzf /helm.tar.gz
 RUN mv /${TARGETOS}-${TARGETARCH}/helm /usr/bin/helm
 
-FROM registry.atmosphere.dev/library/openstack-venv-builder:main AS build
+FROM registry.atmosphere.dev/library/openstack-venv-builder:${RELEASE} AS build
 ARG MAGNUM_GIT_REF=c613ea4e419edc0086116da07e93cf19206746e1
 ADD --keep-git-dir=true https://opendev.org/openstack/magnum.git#${MAGNUM_GIT_REF} /src/magnum
 RUN git -C /src/magnum fetch --unshallow
@@ -31,7 +33,7 @@
         magnum-cluster-api==0.16.0
 EOF
 
-FROM registry.atmosphere.dev/library/openstack-python-runtime:main
+FROM registry.atmosphere.dev/library/openstack-python-runtime:${RELEASE}
 RUN <<EOF bash -xe
 apt-get update -qq
 apt-get install -qq -y --no-install-recommends \