diff --git a/tests/test_cuquantum_cutensor_backend.py b/tests/test_cuquantum_cutensor_backend.py
index c492f9f..79bd36c 100644
--- a/tests/test_cuquantum_cutensor_backend.py
+++ b/tests/test_cuquantum_cutensor_backend.py
@@ -40,6 +40,7 @@ def build_observable_dict(nqubits):
 
     return {"terms": terms}
 
+
 @pytest.mark.gpu
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 10])
 def test_eval(nqubits: int, dtype="complex128"):
@@ -81,6 +82,7 @@ def test_eval(nqubits: int, dtype="complex128"):
         result_sv_cp, result_tn.statevector.flatten()
     ), "Resulting dense vectors do not match"
 
+
 @pytest.mark.gpu
 @pytest.mark.parametrize("nqubits", [2, 5, 10])
 def test_mps(nqubits: int, dtype="complex128"):
diff --git a/tests/test_cuquantum_cutensor_mpi_backend.py b/tests/test_cuquantum_cutensor_mpi_backend.py
index 4b2deef..0fc86e8 100644
--- a/tests/test_cuquantum_cutensor_mpi_backend.py
+++ b/tests/test_cuquantum_cutensor_mpi_backend.py
@@ -43,6 +43,7 @@ def build_observable_dict(nqubits):
 
     return {"terms": terms}
 
+
 @pytest.mark.gpu
 @pytest.mark.mpi
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 7, 10])
@@ -86,6 +87,7 @@ def test_eval_mpi(nqubits: int, dtype="complex128"):
             and result_tn_cp.item() == 0
         ), f"Rank {backend.rank}: result_tn_cp should be scalar/array with 0, got {result_tn_cp}"
 
+
 @pytest.mark.gpu
 @pytest.mark.mpi
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 7, 10])
@@ -177,6 +179,7 @@ def test_expectation_mpi(nqubits: int, dtype="complex128"):
             and result_tn.item() == 0
         ), f"Rank {backend.rank}: expected int array [0], got {result_tn}"
 
+
 @pytest.mark.gpu
 @pytest.mark.mpi
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 7, 10])
@@ -217,6 +220,7 @@ def test_eval_nccl(nqubits: int, dtype="complex128"):
             and result_tn_cp.item() == 0
         ), f"Rank {backend.rank}: result_tn_cp should be scalar/array with 0, got {result_tn_cp}"
 
+
 @pytest.mark.gpu
 @pytest.mark.mpi
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 7, 10])