diff --git a/.github/workflows/test-coverage.yaml b/.github/workflows/test-coverage.yaml
new file mode 100644
index 000000000..21b8a9331
--- /dev/null
+++ b/.github/workflows/test-coverage.yaml
@@ -0,0 +1,50 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
+name: test-coverage
+
+jobs:
+  test-coverage:
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          use-public-rspm: true
+
+      - uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          extra-packages: any::covr
+          needs: coverage
+
+      - name: Test coverage
+        run: |
+          covr::codecov(
+            quiet = FALSE,
+            clean = FALSE,
+            install_path = file.path(normalizePath(Sys.getenv("RUNNER_TEMP"), winslash = "/"), "package")
+          )
+        shell: Rscript {0}
+
+      - name: Show testthat output
+        if: always()
+        run: |
+          ## --------------------------------------------------------------------
+          find '${{ runner.temp }}/package' -name 'testthat.Rout*' -exec cat '{}' \; || true
+        shell: bash
+
+      - name: Upload test results
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-test-failures
+          path: ${{ runner.temp }}/package
diff --git a/codecov.yml b/codecov.yml
index 8f36b6cc1..04c558599 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -6,7 +6,9 @@ coverage:
       default:
         target: auto
         threshold: 1%
+        informational: true
     patch:
       default:
         target: auto
         threshold: 1%
+        informational: true
diff --git a/header.md b/header.md
index e7b365325..0d9224a54 100644
--- a/header.md
+++ b/header.md
@@ -8,6 +8,7 @@
 [![](https://www.r-pkg.org/badges/version/sdmTMB)](https://cran.r-project.org/package=sdmTMB)
 [![Documentation](https://img.shields.io/badge/documentation-sdmTMB-orange.svg?colorB=E91E63)](https://pbs-assess.github.io/sdmTMB/)
 [![R-CMD-check](https://github.com/pbs-assess/sdmTMB/workflows/R-CMD-check/badge.svg)](https://github.com/pbs-assess/sdmTMB/actions)
+[![Codecov test coverage](https://codecov.io/gh/pbs-assess/sdmTMB/branch/main/graph/badge.svg)](https://app.codecov.io/gh/pbs-assess/sdmTMB?branch=main)
 [![downloads](http://cranlogs.r-pkg.org/badges/sdmTMB)](https://cranlogs.r-pkg.org/)
 <!-- badges: end -->