diff --git a/tests/testthat/test-check_residuals.R b/tests/testthat/test-check_residuals.R
new file mode 100644
index 000000000..df92e3505
--- /dev/null
+++ b/tests/testthat/test-check_residuals.R
@@ -0,0 +1,14 @@
+test_that("check_singularity, lme4", {
+  skip_on_cran()
+  skip_if_not_installed("DHARMa")
+  set.seed(123)
+  dat <- DHARMa::createData(sampleSize = 100, overdispersion = 0.5, family = poisson())
+  m <- glm(observedResponse ~ Environment1, family = poisson(), data = dat)
+  res <- simulate_residuals(m)
+  out <- check_residuals(res)
+  expect_equal(out, 0.01884602, ignore_attr = TRUE, tolerance = 1e-4)
+  expect_identical(
+    capture.output(print(out)),
+    "Warning: Non-uniformity of simulated residuals detected (p = 0.019)."
+  )
+})