diff --git a/mne/stats/tests/test_permutations.py b/mne/stats/tests/test_permutations.py
index 2a0b86381b7..245ac140182 100644
--- a/mne/stats/tests/test_permutations.py
+++ b/mne/stats/tests/test_permutations.py
@@ -5,6 +5,7 @@
 from numpy.testing import assert_array_equal, assert_allclose
 import numpy as np
 from scipy import stats, sparse
+import pytest
 
 from mne.stats import permutation_cluster_1samp_test
 from mne.stats.permutations import (
@@ -55,9 +56,25 @@ def test_permutation_t_test():
         assert_allclose(t_obs_clust, t_obs)
         assert_allclose(p_values_clust, p_values[keep], atol=1e-2)
 
+
+@pytest.mark.parametrize(
+    "tail_name,tail_code",
+    [
+        ("two-sided", 0),
+        pytest.param(
+            "less", -1, marks=pytest.mark.xfail(reason="Bug in permutation function")
+        ),
+        pytest.param(
+            "greater", 1, marks=pytest.mark.xfail(reason="Bug in permutation function")
+        ),
+    ],
+)
+def test_permutation_t_test_tail(tail_name, tail_code):
+    """Test that tails work properly."""
     X = np.random.randn(18, 1)
-    t_obs, p_values, H0 = permutation_t_test(X, n_permutations="all")
-    t_obs_scipy, p_values_scipy = stats.ttest_1samp(X[:, 0], 0)
+
+    t_obs, p_values, _ = permutation_t_test(X, n_permutations="all", tail=tail_code)
+    t_obs_scipy, p_values_scipy = stats.ttest_1samp(X[:, 0], 0, alternative=tail_name)
     assert_allclose(t_obs[0], t_obs_scipy, 8)
     assert_allclose(p_values[0], p_values_scipy, rtol=1e-2)