diff --git a/tests/testthat/test-rmse.R b/tests/testthat/test-rmse.R
index 8628760ad..e19bd49b3 100644
--- a/tests/testthat/test-rmse.R
+++ b/tests/testthat/test-rmse.R
@@ -28,6 +28,16 @@ test_that("rmse, ci", {
   # bootstrapped
   set.seed(123)
   out <- performance_rmse(model, ci = 0.95, ci_method = "boot")
-  expect_equal(out$CI_low, 1.9494, tolerance = 1e-4)
-  expect_equal(out$CI_high, 3.38406, tolerance = 1e-4)
+  expect_equal(out$CI_low, 1.9494, tolerance = 1e-3)
+  expect_equal(out$CI_high, 3.38406, tolerance = 1e-3)
+
+  # bootstrapped, mixed models
+  skip_on_cran()
+  skip_if_not_installed("lme4")
+  data(sleepstudy, package = "lme4")
+  m <- lme4::lmer(Reaction ~ Days + (1 | Subject), data = sleepstudy)
+  set.seed(123)
+  out <- performance_rmse(m, ci = 0.95, iterations = 100)
+  expect_equal(out$CI_low, 26.26066, tolerance = 1e-3)
+  expect_equal(out$CI_high, 32.5642, tolerance = 1e-3)
 })