diff --git a/.github/workflows/dotnet-core.yml b/.github/workflows/dotnet-core.yml
index 8d3c3651b..8c49b7f78 100644
--- a/.github/workflows/dotnet-core.yml
+++ b/.github/workflows/dotnet-core.yml
@@ -13,7 +13,13 @@ on:
 jobs:
   build_and_test:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      # Turn on fail-fast once we have the tests running on all platforms
+      fail-fast: false
+      matrix:
+        os: [ ubuntu-latest, windows-latest, macos-latest ]
+
     timeout-minutes: 10
     steps:
     
@@ -32,13 +38,22 @@ jobs:
     - name: Build Debug
       run: dotnet build --configuration Debug --no-restore
 
+    - name: Install sed on macOS
+      if: runner.os == 'macOS'
+      run: |
+          brew install gnu-sed
+          PATH="/opt/homebrew/opt/gnu-sed/libexec/gnubin:$PATH"
+          sed --version
+
       # See https://github.com/microsoft/vstest/issues/2952 for why the --blame stuff below is needed.
       # Without it, the test runner crashes on ubuntu (but not Windows)/
     - name: Test
       run: |
+        PATH="/opt/homebrew/opt/gnu-sed/libexec/gnubin:$PATH"
         sed -i 's/"stopOnFail": false/"stopOnFail": true/g' UnitTests/xunit.runner.json
-        dotnet test --verbosity normal --collect:"XPlat Code Coverage" --settings UnitTests/coverlet.runsettings  --blame --diag:logs/logs.txt --blame-crash --blame-hang --blame-hang-timeout 60s  --blame-crash-collect-always 
-        mv -v UnitTests/TestResults/*/*.* UnitTests/TestResults/
+        dotnet test --verbosity normal --collect:"XPlat Code Coverage" --settings UnitTests/coverlet.runsettings --diag:logs/logs.txt --blame --blame-crash --blame-hang --blame-hang-timeout 60s --blame-crash-collect-always 
+       
+        # mv -v UnitTests/TestResults/*/*.* UnitTests/TestResults/
 
     - name: Upload Test Logs
       if: always()