diff --git a/python_tests/preferential/samplers/test_gp.py b/python_tests/preferential/samplers/test_gp.py
new file mode 100644
index 00000000..33f33cfc
--- /dev/null
+++ b/python_tests/preferential/samplers/test_gp.py
@@ -0,0 +1,30 @@
+import sys
+from unittest.mock import patch
+
+import numpy as np
+import pytest
+import torch
+
+
+if sys.version_info >= (3, 8):
+    from optuna_dashboard.preferential.samplers.gp import _one_side_trunc_norm_sampling
+else:
+    pytest.skip("BoTorch dropped Python3.7 support", allow_module_level=True)
+
+
+def test_one_side_trunc_norm_sampling() -> None:
+    for lower in np.linspace(-10, 10, 100):
+        assert _one_side_trunc_norm_sampling(torch.Tensor([lower])) >= lower
+
+    with patch.object(torch, "rand", return_value=torch.Tensor([0.4])):
+        assert np.allclose(
+            _one_side_trunc_norm_sampling(torch.Tensor([0.1])).numpy(), 0.899967154837563
+        )
+    with patch.object(torch, "rand", return_value=torch.Tensor([0.8])):
+        assert np.allclose(
+            _one_side_trunc_norm_sampling(torch.Tensor([-2.3])).numpy(), -0.8113606739551955
+        )
+    with patch.object(torch, "rand", return_value=torch.Tensor([0.1])):
+        assert np.allclose(
+            _one_side_trunc_norm_sampling(torch.Tensor([5])).numpy(), 5.426934003050024
+        )