diff --git a/.github/workflows/build-image.yaml b/.github/workflows/build-image.yaml
index 9d358c3..7fa31b4 100644
--- a/.github/workflows/build-image.yaml
+++ b/.github/workflows/build-image.yaml
@@ -59,6 +59,21 @@ jobs:
           done
         shell: bash
 
+      - name: Check (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          # Only check the last sub-image in the list (for now)
+          sub=${SUB_IMAGES##* }
+          IMG=$(tr '[:upper:]' '[:lower:]' <<< "${REGISTRY}/${REPOSITORY}/${IMAGE_NAME}-${sub}:${short_sha}")
+          echo "Launching ${IMG}..."
+          docker run \
+            --rm \
+            --volume "${PWD}":/work \
+            --workdir /work \
+            "${IMG}" \
+            "./.github/workflows/test_build_edk2.sh"
+        shell: bash
+
       - name: Push
         if: ${{ github.ref == 'refs/heads/main' }}
         run: |
diff --git a/.github/workflows/test_build_edk2.sh b/.github/workflows/test_build_edk2.sh
new file mode 100755
index 0000000..a719d7c
--- /dev/null
+++ b/.github/workflows/test_build_edk2.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+# Simple smoke-test build of EDK2
+
+set -e
+set -x
+
+if [ -d edk2 ]; then
+  echo "Reusing existing EDK2 source tree."
+  cd edk2
+  echo "  Cleaning up..."
+  git fetch --all
+  git reset --hard origin/master
+  git clean -xdf
+else
+  echo "Pulling fresh EDK2 source tree."
+  git clone --depth=1 "https://github.com/tianocore/edk2.git"
+  cd edk2
+fi
+
+# fixups / workarounds:
+#   removing these files will use gcc from the image and not download it and
+#   run into the python tar bug.
+rm -f BaseTools/Bin/gcc_arm_linux_ext_dep.yaml BaseTools/Bin/gcc_aarch64_linux_ext_dep.yaml
+
+python -m pip install --upgrade pip
+python -m pip install --upgrade -r pip-requirements.txt
+
+stuart_setup -c .pytool/CISettings.py
+stuart_update -c .pytool/CISettings.py
+
+python BaseTools/Edk2ToolsBuild.py -t GCC5
+
+build_step() {
+  build=$1
+  arch=$2
+  opts="TOOL_CHAIN_TAG=GCC5"
+  echo "-----------------------------------------------------------------------"
+  echo "Building ${build} for ${arch}"
+  echo "-----------------------------------------------------------------------"
+  stuart_setup $opts -c "${build}" -a "${arch}"
+  stuart_update $opts -c "${build}" -a "${arch}"
+  stuart_build $opts -c "${build}" -a "${arch}"
+}
+
+build_step "OvmfPkg/PlatformCI/PlatformBuild.py"    "X64"
+build_step "ArmVirtPkg/PlatformCI/PlatformBuild.py" "AARCH64"
+build_step "ArmVirtPkg/PlatformCI/PlatformBuild.py" "ARM"