diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8f5cb8a927..aca57ec45b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,7 +20,11 @@ jobs:
 
   build:
 
-    runs-on: windows-latest
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os: [windows-latest, macos-latest, ubuntu-latest]
 
     steps:
       - name: Set up Node
@@ -48,7 +52,7 @@ jobs:
       - name: Run tests
         run: npm run test
 
-      - name: Upload test coverage
+      - name: Upload test coverage artifact
         uses: actions/upload-artifact@v2-preview
         with:
           name: test-coverage
diff --git a/spec/support/karma.conf.js b/spec/support/karma.conf.js
index 0e3870d8b9..8ba0ec4170 100644
--- a/spec/support/karma.conf.js
+++ b/spec/support/karma.conf.js
@@ -74,9 +74,15 @@ module.exports = (config) => {
                 removeBrowser('Opera');
                 removeBrowser('SafariTechPreview');
 
-                if (process.env.APPVEYOR === 'True') {
+                var ci = process.env.CI === 'True' || process.env.CI === 'true';
+                var githubAction = process.env.GITHUB_WORKFLOW != null && process.env.GITHUB_WORKFLOW !== '';
+                var appveyor = process.env.APPVEYOR === 'True';
+                if (githubAction || appveyor) {
                     removeBrowser('Edge');
                 }
+                if (githubAction) {
+                    removeBrowser('Firefox');
+                }
 
                 return result;
             }