diff --git a/.kokoro/docker/Dockerfile b/.kokoro/docker/Dockerfile
index 0ebde26b525..9cde9491802 100644
--- a/.kokoro/docker/Dockerfile
+++ b/.kokoro/docker/Dockerfile
@@ -14,9 +14,7 @@
 
 # We want to use LTS ubuntu from our mirror because dockerhub has a
 # rate limit.
-# FROM mirror.gcr.io/library/ubuntu:18.04
-# However, now the above image is not working, we're using our own cache
-FROM gcr.io/cloud-devrel-kokoro-resources/ubuntu:20.04
+FROM mirror.gcr.io/library/ubuntu:20.04
 
 ENV DEBIAN_FRONTEND noninteractive
 
@@ -117,7 +115,7 @@ RUN set -ex \
   && export GNUPGHOME="$(mktemp -d)" \
   && echo "disable-ipv6" >> "${GNUPGHOME}/dirmngr.conf" \
   && /tmp/fetch_gpg_keys.sh \
-  && for PYTHON_VERSION in 2.7.18 3.7.17 3.8.17 3.9.17 3.10.12 3.11.4; do \
+  && for PYTHON_VERSION in 2.7.18 3.7.17 3.8.18 3.9.18 3.10.13 3.11.6 3.12.0; do \
   wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" \
   && wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" \
   && gpg --batch --verify python-${PYTHON_VERSION}.tar.xz.asc python-${PYTHON_VERSION}.tar.xz \
@@ -157,6 +155,7 @@ RUN wget --no-check-certificate -O /tmp/get-pip.py 'https://bootstrap.pypa.io/ge
   && [ "$(pip list |tac|tac| awk -F '[ ()]+' '$1 == "pip" { print $2; exit }')" = "$PYTHON_PIP_VERSION" ]
 
 # Ensure Pip for all python3 versions
+RUN python3.12 /tmp/get-pip.py
 RUN python3.11 /tmp/get-pip.py
 RUN python3.9 /tmp/get-pip.py
 RUN python3.8 /tmp/get-pip.py
@@ -170,6 +169,7 @@ RUN python3.8 -m pip
 RUN python3.9 -m pip
 RUN python3.10 -m pip
 RUN python3.11 -m pip
+RUN python3.12 -m pip
 
 # Install "virtualenv", since the vast majority of users of this image
 # will want it.
diff --git a/.kokoro/docker/fetch_gpg_keys.sh b/.kokoro/docker/fetch_gpg_keys.sh
index b4d6554c872..5b8dbbab1ed 100755
--- a/.kokoro/docker/fetch_gpg_keys.sh
+++ b/.kokoro/docker/fetch_gpg_keys.sh
@@ -51,3 +51,7 @@ retry 3 gpg --keyserver keyserver.ubuntu.com --recv-keys \
 # 3.10.x and 3.11.x (Pablo Galindo Salgado)
 retry 3 gpg --keyserver keyserver.ubuntu.com --recv-keys \
       A035C8C19219BA821ECEA86B64E628F8D684696D
+
+# 3.12.x and 3.13.x source files and tags (Thomas Wouters)
+retry 3 gpg --keyserver keyserver.ubuntu.com --recv-keys \
+       A821E680E5FA6305
\ No newline at end of file