diff --git a/src/qibotn/backends/cutensornet.py b/src/qibotn/backends/cutensornet.py
index 05f45af..f7d1270 100644
--- a/src/qibotn/backends/cutensornet.py
+++ b/src/qibotn/backends/cutensornet.py
@@ -18,9 +18,8 @@ CUDA_TYPES = {
 
 class CuTensorNet(NumpyBackend):  # pragma: no cover
     # CI does not test for GPU
-    """Creates CuQuantum backend for QiboTN.
+    """Creates CuQuantum backend for QiboTN."""
 
-    """
     def __init__(self, runcard):
         super().__init__()
         from cuquantum import cutensornet as cutn  # pylint: disable=import-error
@@ -94,7 +93,7 @@ class CuTensorNet(NumpyBackend):  # pragma: no cover
             super().set_precision(precision)
 
     def cuda_type(self, dtype="complex64"):
-        """Get CUDA Type
+        """Get CUDA Type.
 
         Args:
             dtype (str, optional): Either single ("complex64") or double (complex128) precision. Defaults to "complex64".
diff --git a/src/qibotn/circuit_convertor.py b/src/qibotn/circuit_convertor.py
index a15e533..46e7c81 100644
--- a/src/qibotn/circuit_convertor.py
+++ b/src/qibotn/circuit_convertor.py
@@ -26,7 +26,8 @@ class QiboCircuitToEinsum:
         self.circuit = circuit
 
     def state_vector_operands(self):
-        """Create the operands for expectation computation in the interleave format.
+        """Create the operands for expectation computation in the interleave
+        format.
 
         Returns:
             Operands for the contraction in the interleave format.
@@ -198,7 +199,8 @@ class QiboCircuitToEinsum:
         return gates
 
     def expectation_operands(self, pauli_string):
-        """Create the operands for pauli string expectation computation in the interleave format.
+        """Create the operands for pauli string expectation computation in the
+        interleave format.
 
         Args:
             pauli_string: A string representating the list of pauli gates.