diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index f201a70..b5e4790 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -11,10 +11,16 @@ on:
 
 jobs:
   build:
-    runs-on: windows-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.7]
+        os: [macOS-latest, windows-latest]
+        include:  # match Python bitness shipped with Galaxy
+          - os: macOS-latest
+            arch: x64
+          - os: windows-latest
+            arch: x86
+
     steps:
     - name: Checkout code
       uses: actions/checkout@v2
@@ -28,11 +34,9 @@ jobs:
     - name: Build plugin
       uses: GOG-Nebula/action-build-plugin@feat/simple_composite_action
       with:
-        python-arch: 'x86'
+        python-arch: ${{ matrix.arch }}
 
-    - name: Show build dir
-      run: |
-        ls
+    - run: ls
 
     - name: Create zip archive
       shell: bash