diff --git a/.github/conda/conda_build_config.yaml b/.github/conda/conda_build_config.yaml
index 59dbb9f..e8958f1 100644
--- a/.github/conda/conda_build_config.yaml
+++ b/.github/conda/conda_build_config.yaml
@@ -11,6 +11,6 @@ clingo:
 pin_run_as_build:
     clingo: x.x
 
-MACOSX_DEPLOYMENT_TARGET: 11.3  # [osx]
-CONDA_BUILD_SYSROOT:            # [osx]
-    - /opt/MacOSX11.3.sdk       # [osx]
+MACOSX_DEPLOYMENT_TARGET: 10.15  # [osx]
+CONDA_BUILD_SYSROOT:             # [osx]
+    - /opt/MacOSX10.15.sdk       # [osx]
diff --git a/.github/workflows/conda-dev.yml b/.github/workflows/conda-dev.yml
index e255851..0e529d3 100644
--- a/.github/workflows/conda-dev.yml
+++ b/.github/workflows/conda-dev.yml
@@ -42,6 +42,8 @@ jobs:
       if: ${{ matrix.os == 'macos-latest' }}
       shell: pwsh
       run: |
+        Invoke-WebRequest -Uri 'https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX10.15.sdk.tar.xz' -OutFile 'MacOSX10.15.sdk.tar.xz'
+        sudo tar xf MacOSX10.15.sdk.tar.xz -C /opt
         Invoke-WebRequest -Uri 'https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX11.3.sdk.tar.xz' -OutFile 'MacOSX11.3.sdk.tar.xz'
         sudo tar xf MacOSX11.3.sdk.tar.xz -C /opt