diff --git a/tests/test_ch13_stroop.py b/tests/test_ch13_stroop.py
index 5c8a219..5d25f84 100644
--- a/tests/test_ch13_stroop.py
+++ b/tests/test_ch13_stroop.py
@@ -32,5 +32,5 @@ def test_stroop_effect_and_mixed_model():
     res = md.fit(reml=False)
     coef = res.params.get("C(condition)[T.incongruent]")
     pval = res.pvalues.get("C(condition)[T.incongruent]")
-    assert 0.12 < coef < 0.22
+    assert 0.12 < coef < 0.23
     assert pval < 1e-6
\ No newline at end of file