diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 559cfb4a..c9f568b2 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -39,10 +39,17 @@ jobs:
             git -C PawPaw checkout ${PAWPAW_VERSION}
         fi
         ./PawPaw/bootstrap-jack2.sh macos && ./PawPaw/.cleanup.sh macos
+    - name: Build jack2
+      shell: bash
+      run: |
+        pushd PawPaw && source local.env macos && popd
+        ~/PawPawBuilds/targets/macos/bin/python3 ./waf configure --platform=darwin --prefix=/usr/local
+        ~/PawPawBuilds/targets/macos/bin/python3 ./waf build -j $(sysctl -n hw.logicalcpu)
+        ~/PawPawBuilds/targets/macos/bin/python3 ./waf install --destdir="$(pwd)/destdir"
 
   # macOS native universal build
   macos_universal:
-    runs-on: macos-latest
+    runs-on: macos-10.15
     steps:
     - uses: actions/checkout@v2
       with:
@@ -112,6 +119,13 @@ jobs:
             git -C PawPaw checkout ${PAWPAW_VERSION}
         fi
         ./PawPaw/bootstrap-jack2.sh win32 && ./PawPaw/.cleanup.sh win32
+    - name: Build jack2
+      shell: bash
+      run: |
+        pushd PawPaw && source local.env win32 && popd
+        wine ~/PawPawBuilds/targets/win32/bin/python3.exe ./waf configure --platform=win32 --prefix="$(pwd)/destdir" --static
+        wine ~/PawPawBuilds/targets/macos/bin/python3.exe ./waf build -j $(nproc)
+        wine ~/PawPawBuilds/targets/macos/bin/python3.exe ./waf install
 
   # linux with win64 cross-compilation
   win64: