diff --git a/.github/workflows/test-coverage.yaml b/.github/workflows/test-coverage.yaml
new file mode 100644
index 0000000..21b8a93
--- /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/tests/testthat/test-IES.R b/tests/testthat/test-IES.R
index 900281f..6adc05c 100644
--- a/tests/testthat/test-IES.R
+++ b/tests/testthat/test-IES.R
@@ -5,12 +5,12 @@ test_that("IES with RcppArmadillo works", {
   q <- 16
   expect_equal(IES(X, n, q, seed = 123), IES(X, n, q, seed = 123))
 })
-test_that("IES get the same result with R and RcppArmadillo", {
+test_that("IES with R works", {
   data <- data_numeric_regression
   X <- data[-which(names(data) == "y")]
-  n <- 1000
+  n <- 10
   q <- 16
-  expect_equal(r_IES_compare(X, n, q), c_IES_compare(X, n, q))
+  expect_equal(r_IES(X, n, q, seed = 123), r_IES(X, n, q, seed = 123))
 })
 test_that("IES R-version works", {
   data <- data_numeric_regression