diff --git a/.azure/azure-pipelines-mac.yml b/.azure/azure-pipelines-mac.yml
index 64a6c666..18b87dea 100644
--- a/.azure/azure-pipelines-mac.yml
+++ b/.azure/azure-pipelines-mac.yml
@@ -15,23 +15,35 @@ trigger:
 
 jobs:
 - job: macOS
+  strategy:
+    matrix:
+      10_14:
+        imageName: 'macOS-10.14'
+      10_15:
+        imageName: 'macOS-10.15'
+      11_0:
+        imageName: 'macos-11'
+
   pool:
-    vmImage: 'macOS-10.14'
+    vmImage: $(imageName)
 # recommended by https://github.com/Homebrew/brew/issues/2491#issuecomment-294207661
 #        brew update || brew update
 #        brew upgrade $PACKAGES
   steps:
     - script: |
+        set -ex
         PACKAGES="glib gobject-introspection libsndfile pkg-config jack dbus-glib pulseaudio portaudio sdl2 libomp"
         brew install $PACKAGES
       displayName: 'Prerequisites'
     - script: |
+        set -ex
         mkdir build && cd build
         export PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig"
         cmake -Werror=dev -DCMAKE_INSTALL_PREFIX=$(Build.ArtifactStagingDirectory) -DCMAKE_BUILD_TYPE=Release -DCMAKE_VERBOSE_MAKEFILE=1 -DNO_GUI=1 ..
-        make -j`nproc`
+        make -j3
       displayName: 'Compile fluidsynth'
     - script: |
+        set -ex
         cd build || exit -1
-        make -j`nproc` check || exit -1
+        make -j3 check || exit -1
       displayName: 'Execute Unittests'