diff --git a/tests/test_linalg.py b/tests/test_linalg.py
index b978b35b..49a1aaa0 100644
--- a/tests/test_linalg.py
+++ b/tests/test_linalg.py
@@ -94,15 +94,11 @@ def test_matrix_functions():
 
     for (i, j), entry in np.ndenumerate(check):
         diff = entry - sym[i, j]
-        diff.gamma_method()
-        assert math.isclose(diff.value, 0.0, abs_tol=1e-9), 'value ' + str(i) + ',' + str(j)
-        assert math.isclose(diff.dvalue, 0.0, abs_tol=1e-9), 'dvalue ' + str(i) + ',' + str(j)
+        assert diff.is_zero()
 
     # Check eigh
     e, v = pe.linalg.eigh(sym)
     for i in range(dim):
         tmp = sym @ v[:, i] - v[:, i] * e[i]
         for j in range(dim):
-            tmp[j].gamma_method()
-            assert math.isclose(tmp[j].value, 0.0, abs_tol=1e-9), 'value ' + str(i) + ',' + str(j)
-            assert math.isclose(tmp[j].dvalue, 0.0, abs_tol=1e-9), 'dvalue ' + str(i) + ',' + str(j)
+            assert tmp[j].is_zero()
diff --git a/tests/test_pyerrors.py b/tests/test_pyerrors.py
index 2740d5d9..39192c6f 100644
--- a/tests/test_pyerrors.py
+++ b/tests/test_pyerrors.py
@@ -245,4 +245,4 @@ def test_cobs():
         assert np.allclose(0.0, diff.real.deltas['t'])
         assert np.allclose(0.0, diff.imag.deltas['t'])
 
-        div = my_cobs / other
+        assert (my_cobs / other * other - my_cobs).is_zero()