diff --git a/pytket/extensions/qiskit/backends/crosstalk_model.py b/pytket/extensions/qiskit/backends/crosstalk_model.py
index e444096d..e405b252 100644
--- a/pytket/extensions/qiskit/backends/crosstalk_model.py
+++ b/pytket/extensions/qiskit/backends/crosstalk_model.py
@@ -40,7 +40,8 @@
 @dataclass
 class FractionalUnitary:
     """
-    Wrapper for a fractional unitary gate
+    Wrapper for a fractional unitary gate.
+
     :param cmd: the fractional UnitaryBox wrapped in a pytket Command
     :param n_fractions: the number of fractional gates
         used to compose the original unitary gate.