diff --git a/nifty4/operators/linear_operator.py b/nifty4/operators/linear_operator.py
index aedce314c7034c47cf6e719d5b96c2c2901e4e30..97dd6ee5bbbb2988bfbcfd7a0177ee6f36d9a87d 100644
--- a/nifty4/operators/linear_operator.py
+++ b/nifty4/operators/linear_operator.py
@@ -98,7 +98,8 @@ class LinearOperator(NiftyMetaBase()):
 
     def _flip_modes(self, op_transform):
         from .operator_adapter import OperatorAdapter
-        return self if op_transform == 0 else OperatorAdapter(self, op_transform)
+        return self if op_transform == 0 \
+            else OperatorAdapter(self, op_transform)
 
     @property
     def inverse(self):
diff --git a/nifty4/operators/operator_adapter.py b/nifty4/operators/operator_adapter.py
index 74755c72d419c7e859d36bfc786afa3932c7e20d..01bfb79e336737740ba4d829975049cb4196b3ef 100644
--- a/nifty4/operators/operator_adapter.py
+++ b/nifty4/operators/operator_adapter.py
@@ -47,7 +47,8 @@ class OperatorAdapter(LinearOperator):
         return self._op if newmode == 0 else OperatorAdapter(self._op, newmode)
 
     def apply(self, x, mode):
-        return self._op.apply(x, self._modeTable[self._trafo][self._ilog[mode]])
+        return self._op.apply(x,
+                              self._modeTable[self._trafo][self._ilog[mode]])
 
     def draw_sample(self, from_inverse=False, dtype=np.float64):
         if self._trafo & self.INVERSE_BIT: