diff --git a/diffmah/tests/test_utils.py b/diffmah/tests/test_utils.py
index 9805212..0b51412 100644
--- a/diffmah/tests/test_utils.py
+++ b/diffmah/tests/test_utils.py
@@ -4,6 +4,7 @@
 import numpy as np
 from jax import jit as jax_jit
 from jax import numpy as jax_np
+from jax import random as jran
 from jax import value_and_grad
 
 from ..utils import (
@@ -126,9 +127,11 @@ def test_get_cholesky_from_params1():
 def test_trimmed_mean_agrees_with_scipy():
     from scipy.stats.mstats import trimmed_mean as trimmed_mean_scipy
 
+    ran_key = jran.key(0)
     ptest = 0.1, 0.2, 0.3
     for p in ptest:
-        x = np.random.normal(loc=0, scale=1, size=20_000)
+        ran_key, test_key = jran.split(ran_key, 2)
+        x = jran.normal(test_key, shape=(20_000,))
         mu_p10 = trimmed_mean(x, p)
         mu_p10_scipy = trimmed_mean_scipy(x, p)
         assert np.allclose(mu_p10, mu_p10_scipy, rtol=0.01)
@@ -138,9 +141,11 @@ def test_trimmed_mean_and_variance_agrees_with_scipy():
     from scipy.stats.mstats import trimmed_mean as trimmed_mean_scipy
     from scipy.stats.mstats import trimmed_var as trimmed_var_scipy
 
+    ran_key = jran.key(0)
     ptest = 0.01, 0.1, 0.2, 0.3
     for p in ptest:
-        x = np.random.normal(loc=0, scale=1, size=20_000)
+        ran_key, test_key = jran.split(ran_key, 2)
+        x = jran.normal(test_key, shape=(20_000,))
         mu_p10, var_p10 = trimmed_mean_and_variance(x, p)
         mu_p10_scipy = trimmed_mean_scipy(x, p)
         var_p10_scipy = trimmed_var_scipy(x, p)
@@ -149,7 +154,8 @@ def test_trimmed_mean_and_variance_agrees_with_scipy():
 
 
 def test_trimmed_mean_and_variance_consistency():
-    x = np.random.normal(loc=0, scale=1, size=20_000)
+    ran_key = jran.key(0)
+    x = jran.normal(ran_key, shape=(20_000,))
     mu, var = trimmed_mean_and_variance(x, 0.1)
     mu2 = trimmed_mean(x, 0.1)
     assert np.allclose(mu, mu2, rtol=1e-4)