diff --git a/tests/test_benchmark.py b/tests/test_benchmark.py
index 089c78b4e..641e0f243 100644
--- a/tests/test_benchmark.py
+++ b/tests/test_benchmark.py
@@ -9,13 +9,14 @@
 
 def vectorize_data(model: js.model.JaxSimModel, batch_size: int):
     key = jax.random.PRNGKey(seed=0)
+    keys = jax.random.split(key, num=batch_size)
 
     return jax.vmap(
         lambda key: js.data.random_model_data(
             model=model,
             key=key,
         )
-    )(jax.numpy.repeat(key[None, :], repeats=batch_size, axis=0))
+    )(keys)
 
 
 def benchmark_test_function(