diff --git a/tests/testthat/test-find_weights.R b/tests/testthat/test-find_weights.R
index dd010acf9..03da140e2 100644
--- a/tests/testthat/test-find_weights.R
+++ b/tests/testthat/test-find_weights.R
@@ -2,14 +2,16 @@ skip_if_not_installed("lme4")
 
 test_that("find_weights", {
   data(mtcars)
-  mtcars$weight <- rnorm(nrow(mtcars), 1, 0.3)
+  set.seed(123)
+  mtcars$weight <- abs(rnorm(nrow(mtcars), 1, 0.3))
   m <- lm(mpg ~ wt + cyl + vs, data = mtcars, weights = weight)
   expect_identical(find_weights(m), "weight")
 })
 
 test_that("find_weights", {
   data(iris)
-  iris$wgt <- rnorm(nrow(iris), 1, 0.3)
+  set.seed(123)
+  iris$wgt <- abs(rnorm(nrow(iris), 1, 0.3))
   m <- lme4::lmer(Sepal.Width ~ Sepal.Length + (1 | Species), data = iris, weights = wgt)
   expect_identical(find_weights(m), "wgt")
 })