diff --git a/.github/workflows/artifacts.yaml b/.github/workflows/artifacts.yaml
index 0cf179ff..23228e11 100644
--- a/.github/workflows/artifacts.yaml
+++ b/.github/workflows/artifacts.yaml
@@ -146,3 +146,122 @@ jobs:
         with:
           name: rustls-ffi-x86_64-macos
           path: x86-dist
+
+  test-archives:
+    name: "Test (${{ matrix.os }})"
+    runs-on: ${{ matrix.os }}
+    needs: [ windows-binaries, linux-binaries, macos-binaries ]
+    strategy:
+      matrix:
+        include:
+          - os: windows-latest
+            artifact: rustls-ffi-x86_64-windows
+          - os: ubuntu-latest
+            artifact: rustls-ffi-x86_64-linux-gnu
+          - os: macos-14
+            artifact: rustls-ffi-arm64-macos
+          - os: macos-13
+            artifact: rustls-ffi-x86_64-macos
+    steps:
+      - name: Checkout rustls-ffi-test sources
+        uses: actions/checkout@v4
+        with:
+          repository: 'cpu/rustls-ffi-test'
+      - name: Download rustls-ffi artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ matrix.artifact }}
+          path: ${{ matrix.artifact }}
+      # .pc files aren't relocatable. We need to update the prefix to point to
+      # the correct location that we extracted the archive. This seems more reliable
+      # than using `--define-prefix` - it seems to tack an extra 'lib/' subcomponent
+      # onto the include path that breaks the build.
+      - name: Fix pkg-config prefix
+        # We use bash shell explicitly to avoid PowerShell on Windows and to ensure we have 'sed'.
+        shell: bash
+        # For further fun, sed isn't consistent between macOS and Linux.
+        run: |
+          case "${{ runner.os }}" in
+            "macOS")
+              sed -i '' "s|prefix=.*|prefix=${{ matrix.artifact }}|" ${{ matrix.artifact }}/lib/pkgconfig/rustls.pc
+              ;;
+            *)
+              sed -i "s|prefix=.*|prefix=${{ matrix.artifact }}|" ${{ matrix.artifact }}/lib/pkgconfig/rustls.pc
+              ;;
+          esac
+      # Dump out what pkg-config says about the rustls package.
+      - name: Debug pkg-config
+        run: |
+          pkg-config --cflags rustls
+          pkg-config --libs rustls
+        env:
+          PKG_CONFIG_PATH: ${{ matrix.artifact }}/lib/pkgconfig
+      # Set up the cmake build, overriding PKG_CONFIG_PATH to
+      # point to the extracted rustls-ffi archive.
+      - name: Setup cmake build (UNIX)
+        if: matrix.os != 'windows-latest'
+        env:
+          PKG_CONFIG_PATH: ${{ matrix.artifact }}/lib/pkgconfig
+        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+      # Set up the cmake build, overriding PKG_CONFIG_PATH to
+      # point to the extracted rustls-ffi archive.
+      #
+      # For Windows cmake needs some help finding the strawberry perl pkg-config
+      # that's installed in the runner's PATH.
+      - name: Setup cmake build (Windows)
+        if: matrix.os == 'windows-latest'
+        env:
+          PKG_CONFIG_PATH: ${{ matrix.artifact }}/lib/pkgconfig
+        run: cmake -DPKG_CONFIG_EXECUTABLE=C:\Strawberry\perl\bin\pkg-config.bat -S . -B build
+      # Build the rustls-ffi-test binary.
+      - name: Build rustls-ffi-test (UNIX)
+        if: matrix.os != 'windows-latest'
+        run: cmake --build build -v
+      # Build the rustls-ffi-test binary.
+      # On Windows we need to specify a configuration to avoid a warning about using the default
+      # debug MSCRT runtime with a lib built with the release MSCRT runtime.
+      - name: Build rustls-ffi-test (Windows)
+        if: matrix.os == 'windows-latest'
+        run: cmake --build build --config Release -v
+      # Run the rustls-ffi-test binary.
+      - name: Run rustls-ffi-test (UNIX)
+        if: matrix.os != 'windows-latest'
+        run: ./build/rustls-ffi-test
+      # Run the rustls-ffi-test binary.
+      # On Windows it's in a different output location under build.
+      - name: Run rustls-ffi-test (Windows)
+        if: matrix.os == 'windows-latest'
+        run: ./build/Release/rustls-ffi-test.exe
+
+  test-deb:
+    name: "Test Linux Deb (${{ matrix.os }})"
+    runs-on: ${{ matrix.os }}
+    needs: [ linux-deb ]
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, ubuntu-20.04 ]
+    steps:
+      - name: Checkout rustls-ffi-test sources
+        uses: actions/checkout@v4
+        with:
+          repository: 'cpu/rustls-ffi-test'
+      - name: Download rustls-ffi deb artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: librustls_0.15.0_amd64.deb
+      - name: Install deb
+        run: sudo dpkg --install ./librustls_0.15.0_amd64.deb
+      # Dump out what pkg-config says about the rustls package.
+      - name: Debug pkg-config
+        run: |
+          pkg-config --cflags rustls
+          pkg-config --libs rustls
+      # Set up the cmake build, no pkg-config ENV overrides needed.
+      - name: Setup cmake build
+        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+      # Build the rustls-ffi-test binary.
+      - name: Build rustls-ffi-test
+        run: cmake --build build -v
+      # Run the rustls-ffi-test binary.
+      - name: Run rustls-ffi-test
+        run: ./build/rustls-ffi-test