diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
index fc2830a..d9ac677 100644
--- a/.github/workflows/docker-publish.yml
+++ b/.github/workflows/docker-publish.yml
@@ -31,7 +31,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       # Install the cosign tool except on PR
       # https://github.com/sigstore/cosign-installer
diff --git a/.github/workflows/vcpkg-bumper.yml b/.github/workflows/vcpkg-bumper.yml
index f1f216d..f4825fc 100644
--- a/.github/workflows/vcpkg-bumper.yml
+++ b/.github/workflows/vcpkg-bumper.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Find latest vcpkg version
         id: latest_vcpkg
diff --git a/Dockerfile b/Dockerfile
index 6441818..2d52208 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,15 +4,12 @@
 # pin the cmake version to ensure repeatable builds
 ARG CMAKE_VERSION="3.26.3"
 ARG VCPKG_VERSION="2024.03.25"
-# patch releases are automatically accepted by pip install ninja~=1.11.0
-ARG NINJA_MINOR_VERSION="1.11.0"
 
-# Ubuntu Bionic 18.04 LTS has GLIBC 2.27
-FROM ubuntu:bionic
+# Ubuntu Bionic 20.04 LTS has GLIBC 2.31
+FROM ubuntu:focal
 
 ARG CMAKE_VERSION
 ARG VCPKG_VERSION
-ARG NINJA_MINOR_VERSION
 ARG XDG_CONFIG_HOME
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -42,13 +39,18 @@ RUN apt-get update \
         doxygen \
         expect \
         flex \
+        g++-arm-linux-gnueabihf \
+        gcc-aarch64-linux-gnu \
+        gcc-arm-linux-gnueabihf \
         gcovr \
+        git \
         gpg \
         graphviz \
         libcap-dev \
         libssl-dev \
         libsystemd-dev \
         libtool \
+        ninja-build \
         pkg-config \
         python3 \
         python3-pip \
@@ -62,19 +64,13 @@ RUN apt-get update \
     && apt-get clean autoclean \
     && rm -fr /var/lib/apt/lists/{apt,dpkg,cache,log} /tmp/* /var/tmp/*
 
-# provides patch releases for 1.11 in /usr/local/bin/ninja
-RUN python3 -m pip install ninja~=${NINJA_MINOR_VERSION}
-
 RUN curl -sSLf https://apt.llvm.org/llvm-snapshot.gpg.key \
     | gpg --dearmor --output /usr/share/keyrings/llvm-snapshot.gpg \
     && chmod +r /usr/share/keyrings/llvm-snapshot.gpg \
-    && echo "deb [signed-by=/usr/share/keyrings/llvm-snapshot.gpg] http://apt.llvm.org/bionic/ llvm-toolchain-bionic-17 main" > /etc/apt/sources.list.d/llvm-snapshot.list
+    && echo "deb [signed-by=/usr/share/keyrings/llvm-snapshot.gpg] http://apt.llvm.org/focal/ llvm-toolchain-focal-17 main" > /etc/apt/sources.list.d/llvm-snapshot.list
 
-# when we migrate this builder to focal or newer, just remove this ppa and the rest should work
-RUN add-apt-repository ppa:git-core/ppa \
-    && apt-get update \
+RUN apt-get update \
     && apt-get --yes --quiet --no-install-recommends install \
-        git \
         clang-17 \
         clang-tidy-17 \
     && apt-get --yes autoremove \
diff --git a/README.md b/README.md
index c8e9f70..59c19f5 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ to build the project.
 
 ```bash
 # optionally substitute podman or nerdctl for docker
-docker build ./docker-image/ --tag ziti-builder-test
+docker build . --tag ziti-builder-test
 ```
 
 ### Run the local test image to cross-compile a Ziti project
diff --git a/crossbuild.list b/crossbuild.list
index f4fb8ab..92bd6a6 100644
--- a/crossbuild.list
+++ b/crossbuild.list
@@ -1,7 +1,7 @@
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic main restricted
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic-updates main restricted
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic universe
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic-updates universe
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic multiverse
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic-updates multiverse
-deb [arch=armhf,arm64] http://ports.ubuntu.com/ bionic-backports main restricted universe multiverse
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal main restricted
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal-updates main restricted
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal universe
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal-updates universe
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal multiverse
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal-updates multiverse
+deb [arch=armhf,arm64] http://ports.ubuntu.com/ focal-backports main restricted universe multiverse