diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
new file mode 100644
index 0000000..5da7dbe
--- /dev/null
+++ b/.github/workflows/coverage.yml
@@ -0,0 +1,36 @@
+# Measure code coverage using Codecov
+
+name: coverage
+
+on:
+  push:
+    branches: master
+  pull_request:
+    branches: master
+
+jobs:
+  run:
+    name: Measure code coverage
+    runs-on: ubuntu-latest
+    steps:
+    - name: Install lcov
+      run: sudo apt install -y lcov
+    - name: Get source
+      uses: actions/checkout@v3
+    - name: Configure CMake
+      run: >
+        CXX=g++ cmake -B ${{github.workspace}}/build 
+        -DCMAKE_BUILD_TYPE=Coverage
+    - name: Build
+      run: cmake --build ${{github.workspace}}/build
+    - name: Run tests
+      working-directory: ${{github.workspace}}/build
+      run: |
+        lcov -c -i -d .. -o coverage_base.info
+        test/testgf2
+    - name: Upload coverage reports to Codecov
+      working-directory: ${{github.workspace}}/build
+      run: |
+        lcov -c -d .. -o coverage_test.info
+        lcov -a coverage_base.info -a coverage_test.info -o coverage.info
+        bash <(curl -s https://codecov.io/bash) -f coverage.info
diff --git a/.gitignore b/.gitignore
index 270e6c7..607ab3c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,7 +60,5 @@
 # Specific files
 .aux
 apps
-backup
 build
-support
 clear.cmd