diff --git a/tests/test_core.py b/tests/test_core.py
index <HASH>..<HASH> 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -1465,6 +1465,19 @@ def test_pcen():
     #   gain=1, bias=0, power=1, b=1, eps=1e-20 => ones
     yield __test, 1, 0, 1, 1.0, 0.5, 1e-20, 1, S, np.ones_like(S)
 
+    # Dynamic range compression. Disjunction of cases
+    #   gain=0, bias=1, power=0
+    P = librosa.pcen(S, gain=0.0, bias=1.0, power=0.0, eps=1e-20)
+    assert np.allclose(S, np.expm1(P))
+
+    #   gain=0, bias=0, power=1e-3
+    P = librosa.pcen(S, gain=0.0, bias=0.0, power=1e-3, eps=1e-20)
+    assert np.allclose(S, np.exp(1e3*np.log(P)))
+
+    #   gain=0, bias=1, power=1e-3
+    P = librosa.pcen(S, gain=0.0, bias=1.0, power=1e-3, eps=1e-20)
+    assert np.allclose(S, np.expm1(1e3*np.log1p(P)))
+
     # Catch the complex warning
     yield __test, 1, 0, 1, 1.0, 0.5, 1e-20, 1, S * 1.j, np.ones_like(S)
test dynamic range compression in pcen