diff --git a/extensions/Dockerfile b/extensions/Dockerfile
index f1430c0c2..d2e0b5403 100644
--- a/extensions/Dockerfile
+++ b/extensions/Dockerfile
@@ -22,10 +22,10 @@ RUN if [[ -n "${VARIANT}" ]]; then MANIFEST="manifest-${VARIANT}.yaml"; EXTENSIO
 ## Creates the repo metadata for the extensions.
 ## This uses Fedora as a lowest-common-denominator because it will work on
 ## current p8/s390x. See https://github.com/openshift/os/issues/1000
-FROM quay.io/fedora/fedora:latest as builder
+FROM quay.io/fedora/fedora:40 as builder
 COPY --from=os /usr/share/rpm-ostree/extensions/ /usr/share/rpm-ostree/extensions/
 RUN rm -f /etc/yum.repos.d/*.repo \
-&& curl -L https://raw.githubusercontent.com/coreos/fedora-coreos-config/testing-devel/fedora.repo -o /etc/yum.repos.d/fedora.repo
+&& curl -L https://raw.githubusercontent.com/coreos/fedora-coreos-config/testing-devel/fedora-archive.repo -o /etc/yum.repos.d/fedora-archive.repo
 RUN dnf install -y createrepo_c
 RUN createrepo_c /usr/share/rpm-ostree/extensions/