diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index 9dec7f23..0e19d159 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -19,10 +19,6 @@ jobs:
           # Need to quote decimal versions as string to avoid the "Norway problem"
 
           # Windows 64-bit
-          - os: windows-latest
-            python: '3.9'
-            cibw_python: 39
-            platform_id: win_amd64
           - os: windows-latest
             python: '3.10'
             cibw_python: 310
@@ -59,25 +55,23 @@ jobs:
             platform_id: manylinux_x86_64
 
           # macOS on Intel 64-bit
-          - os: macos-12
-            python: '3.9'
-            cibw_python: 39
-            arch: x86_64
-            platform_id: macosx_x86_64
           - os: macos-12
             python: '3.10'
             cibw_python: 310
             arch: x86_64
+            macos_target: 10.14
             platform_id: macosx_x86_64
           - os: macos-12
             python: '3.11'
             cibw_python: 311
             arch: x86_64
+            macos_target: 10.14
             platform_id: macosx_x86_64
           - os: macos-12
             python: '3.12'
             cibw_python: 312
             arch: x86_64
+            macos_target: 10.14
             platform_id: macosx_x86_64
 
           # macOS on Apple M1 64-bit, supported for Python 3.10 and later
@@ -85,16 +79,19 @@ jobs:
             python: '3.10'
             cibw_python: 310
             arch: arm64
+            macos_target: 11.0
             platform_id: macosx_arm64
           - os: macos-14
             python: '3.11'
             cibw_python: 311
             arch: arm64
+            macos_target: 11.0
             platform_id: macosx_arm64
           - os: macos-14
             python: '3.12'
             cibw_python: 312
             arch: arm64
+            macos_target: 11.0
             platform_id: macosx_arm64
 
     steps:
@@ -112,7 +109,17 @@ jobs:
         if: matrix.platform_id == 'win_amd64'
         uses: ilammy/msvc-dev-cmd@v1
 
+      # conda to get libpng on Mac that is compatible with more OS versions
+      # brew install libpng has a mininum OS of 12
+      - name: Set up Conda
+        if: startsWith(matrix.os, 'macos-')
+        uses: conda-incubator/setup-miniconda@v3
+        with:
+          auto-update-conda: true
+          python-version: ${{ matrix.python }}
+
       - name: Install cibuildwheel
+        shell: bash -el {0}
         run: python -m pip install cibuildwheel==2.19.2 setuptools toml
 
       - name: Get package name and version (Linux / Mac)
@@ -129,13 +136,14 @@ jobs:
           echo "PACKAGE_NAME=$( python -c "import toml; print(toml.load('pyproject.toml')['project']['name'])" )" | Out-File -FilePath $env:GITHUB_ENV ` -Append
           echo "PACKAGE_VERSION=$( python -c "import toml; print(toml.load('pyproject.toml')['project']['version'])" )" | Out-File -FilePath $env:GITHUB_ENV ` -Append
 
-      - name: Determine macOS version
+      # Do this before CIBW steps
+      - name: Set MacOS deployment target
         if: startsWith(matrix.os, 'macos-')
         run: |
-          macos_version=$(sw_vers -productVersion | awk -F '.' '{print $1".0"}')
-          echo "MACOSX_DEPLOYMENT_TARGET=${macos_version}" >> $GITHUB_ENV
+          echo "MACOSX_DEPLOYMENT_TARGET=${{ matrix.macos_target }}" >> $GITHUB_ENV
 
       - name: Build wheels
+        shell: bash -el {0}
         env:
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux2014
           CIBW_MANYLINUX_I686_IMAGE: manylinux2014
@@ -157,19 +165,17 @@ jobs:
           CIBW_ARCHS_MACOS: ${{ matrix.arch }}
 
           CIBW_ENVIRONMENT_MACOS: |
-            CMAKE_OSX_ARCHITECTURES=${{ matrix.arch }} CMAKE_PREFIX_PATH=/usr/local
+            CMAKE_OSX_ARCHITECTURES=${{ matrix.arch }}
 
           CIBW_BEFORE_ALL_MACOS: |
             python -m pip install cmake ninja setuptools
-            brew update
-            if ! brew list libpng &>/dev/null; then
-                HOMEBREW_NO_AUTO_UPDATE=1 brew install libpng
-            fi
+            conda install libpng
 
         run: python -m cibuildwheel --output-dir wheelhouse/cp${{ matrix.cibw_python }}-${{matrix.platform_id }}
 
       - name: Install and test (Linux / Mac)
         if: ${{ ! startsWith(matrix.os, 'windows-') }}
+        shell: bash -el {0}
         run: |
           python -m pip install wheelhouse/cp${{ matrix.cibw_python }}-${{matrix.platform_id }}/*.whl
           tests/run_tests.sh
@@ -219,4 +225,4 @@ jobs:
           password: ${{ secrets.PYPI_API_TOKEN }}
           verify_metadata: false
           skip_existing: true
-          verbose: true
+          verbose: true
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