diff --git a/nifty5/operators/energy_operators.py b/nifty5/operators/energy_operators.py
index 1e8b761f447f45e3dfb6acb9eea5c19689c7c5d0..d6d3170ca5cc6494e7f4a2d80c27452c65bf497d 100644
--- a/nifty5/operators/energy_operators.py
+++ b/nifty5/operators/energy_operators.py
@@ -65,6 +65,7 @@ class Squared2NormOperator(EnergyOperator):
             return x.new(val, jac)
         return Field.scalar(x.vdot(x))
 
+
 class QuadraticFormOperator(EnergyOperator):
     """Computes the L2-norm of a Field or MultiField with respect to a
     specific kernel given by `endo`.
diff --git a/nifty5/operators/log1p.py b/nifty5/operators/log1p.py
index 016f1c71001a499fc81e7ed6ea08c169274ab0a6..2dca0c3144b6ab11a9b731acc51f75aa83ee4e12 100644
--- a/nifty5/operators/log1p.py
+++ b/nifty5/operators/log1p.py
@@ -40,4 +40,3 @@ class Log1p(Operator):
             return res
         jac = DiagonalOperator(1/(1+xval))
         return x.new(res, jac@x.jac)
-
diff --git a/test/test_energy_gradients.py b/test/test_energy_gradients.py
index 4b117c83ac517b7db8beb9bfbac5d9f6239efcbb..0e6a9371f0a40ea69be5816d64a02e6fc0ec5f49 100644
--- a/test/test_energy_gradients.py
+++ b/test/test_energy_gradients.py
@@ -46,10 +46,12 @@ def test_gaussian(field):
     energy = ift.GaussianEnergy(domain=field.domain)
     ift.extra.check_jacobian_consistency(energy, field)
 
+
 def test_studentt(field):
     energy = ift.StudentTEnergy(domain=field.domain, theta=.5)
     ift.extra.check_jacobian_consistency(energy, field, tol=1e-6)
 
+
 def test_inverse_gamma(field):
     field = field.exp()
     space = field.domain