diff --git a/src/eko/member.py b/src/eko/member.py
index f03b0e9b4..edf8f89a3 100644
--- a/src/eko/member.py
+++ b/src/eko/member.py
@@ -266,7 +266,7 @@ def operator_multiply(left, right, operation):
                     new_oms[new_key] += operation(l_op, r_op)
         return new_oms
 
-    def to_flavor_basis_tensor(self, qed: bool = False):
+    def to_flavor_basis_tensor(self, qed: bool):
         """Convert the computations into an rank 4 tensor.
 
         A sparse tensor defined with dot-notation (e.g. ``S.g``) is converted
diff --git a/tests/eko/evolution_operator/test_physical.py b/tests/eko/evolution_operator/test_physical.py
index b4a9936b6..e9882de5b 100644
--- a/tests/eko/evolution_operator/test_physical.py
+++ b/tests/eko/evolution_operator/test_physical.py
@@ -138,7 +138,7 @@ def test_to_flavor_basis_tensor_ss(self):
             ),
             1,
         )
-        vt, _ = a.to_flavor_basis_tensor()
+        vt, _ = a.to_flavor_basis_tensor(False)
         np.testing.assert_allclose(vt[6, :, 6, :], vt[6, :, 5, :])
         np.testing.assert_allclose(vt[6, :, 6, :], vt[5, :, 6, :])
         np.testing.assert_allclose(vt[6, :, 6, :], SS.value[:, :] / (2 * 3))
@@ -158,7 +158,7 @@ def test_to_flavor_basis_tensor_gg(self):
             ),
             1,
         )
-        vt, _ = a.to_flavor_basis_tensor()
+        vt, _ = a.to_flavor_basis_tensor(False)
         np.testing.assert_allclose(vt[6, :, 6, :], 0)
         np.testing.assert_allclose(vt[7, :, 7, :], gg.value[:, :])
         np.testing.assert_allclose(vt[1, :, :, :], 0)
@@ -199,7 +199,7 @@ def test_to_flavor_basis_tensor_gg_qed(self):
             ),
             1,
         )
-        vt, _ = a.to_flavor_basis_tensor()
+        vt, _ = a.to_flavor_basis_tensor(False)
         np.testing.assert_allclose(vt[6, :, 6, :], 0)
         np.testing.assert_allclose(vt[7, :, 7, :], gg.value[:, :])
         np.testing.assert_allclose(vt[1, :, :, :], 0)