diff --git a/src/qibo/backends/__init__.py b/src/qibo/backends/__init__.py
index e8d8e274fd..f0a7c2e742 100644
--- a/src/qibo/backends/__init__.py
+++ b/src/qibo/backends/__init__.py
@@ -33,10 +33,10 @@ def construct_backend(backend, **kwargs):
 
     elif backend == "qibolab":  # pragma: no cover
         from qibolab.backends import QibolabBackend  # pylint: disable=E0401
-        
+
     elif backend == "qibotn":  # pragma: no cover
         from qibotn.backends import CuTensorNet, QuimbBackend  # pylint: disable=E0401
- 
+
         if platform == "cutensornet":  # pragma: no cover
             return CuTensorNet(runcard)
         elif platform == "qutensornet":  # pragma: no cover