diff --git a/1d_separation.py b/1d_separation.py
index 012b542f6a6c6a3d68d120ec504dd43241a540e3..f90f0dd32fa631b3d424a87aee32c321d20fd03d 100644
--- a/1d_separation.py
+++ b/1d_separation.py
@@ -9,12 +9,12 @@ from matplotlib import pyplot as plt
 np.random.seed(42)
 if __name__ == '__main__':
     s_space = ift.RGSpace([1024])
-    FFT = ift.FFTOperator(s_space)
-    h_space = FFT.target[0]
+    h_space = s_space.get_default_codomain()
+    FFT = ift.FFTOperator(h_space)
     p_spec = lambda k: (1./(1+k)**2.5)
     S = ift.create_power_operator(h_space, power_spectrum=p_spec)
     sh = S.draw_sample()
-    s = FFT.adjoint_times(sh)
+    s = FFT(sh)
 
     u = ift.Field(s_space, val = -12)
     u.val[200] = 1
diff --git a/point_separation.py b/point_separation.py
index 3b68e9901ed6c815344b4977cd05594562d076e1..e5fa14b3aef6df434adbd048f3a4b768c128b0f9 100644
--- a/point_separation.py
+++ b/point_separation.py
@@ -18,12 +18,12 @@ def load_data(path):
 
 def build_problem(data, alpha):
     s_space = ift.RGSpace(data.shape, distances=len(data.shape) * [1])
+    h_space = s_space.get_default_codomain()
     data = ift.Field(s_space,val=data)
-    FFT = ift.FFTOperator(s_space)
-    h_space = FFT.target[0]
+    FFT = ift.FFTOperator(h_space)
     binbounds = ift.PowerSpace.useful_binbounds(h_space, logarithmic = False)
     p_space = ift.PowerSpace(h_space, binbounds=binbounds)
-    initial_spectrum = ift.power_analyze(FFT(ift.log(data)), binbounds=p_space.binbounds)
+    initial_spectrum = ift.power_analyze(FFT.inverse_times(ift.log(data)), binbounds=p_space.binbounds)
     initial_correlation = ift.create_power_operator(h_space, initial_spectrum)
     initial_x = ift.Field(s_space, val=-1.)
     alpha = ift.Field(s_space, val=alpha)
@@ -47,7 +47,7 @@ def problem_iteration(energy, iterations=3):
     h_space = energy.correlation.domain[0]
     FFT = energy.FFT
     binbounds = ift.PowerSpace.useful_binbounds(h_space, logarithmic=False)
-    new_power = ift.power_analyze(FFT(energy.s), binbounds=binbounds)
+    new_power = ift.power_analyze(FFT.inverse_times(energy.s), binbounds=binbounds)
     new_correlation = ift.create_power_operator(h_space, new_power)
     new_parameters = energy.parameters
     new_parameters['correlation'] = new_correlation
diff --git a/separation_energy.py b/separation_energy.py
index ca44a76402e8e154ef1d0fa252b6b990efeafb3e..76d7810d02eeff052e749ea7497bd381d095745c 100644
--- a/separation_energy.py
+++ b/separation_energy.py
@@ -19,7 +19,7 @@ class SeparationEnergy(Energy):
         self.q = parameters['q']
         pos_tanh = parameters['pos_tanh']
 
-        self.S = self.FFT.adjoint * self.correlation * self.FFT
+        self.S = self.FFT * self.correlation * self.FFT.adjoint
         self.a = pos_tanh(self.position)
         self.a_p = pos_tanh.derivative(self.position)
 
@@ -52,7 +52,7 @@ class SeparationEnergy(Energy):
     @property
     def curvature(self):
         point = self.q * exp(-self.u) * self.u_p ** 2
-        R = self.FFT * self.s_p
+        R = self.FFT.inverse * self.s_p
         N = self.correlation
         S = DiagonalOperator(1/(point + 1/self.var_x))
         return WienerFilterCurvature(R=R, N=N, S=S, inverter=self.inverter)