diff --git a/demos/bernoulli_demo.py b/demos/bernoulli_demo.py
index 76fec1a116c4f7d804ff108e6935645d6e4e06ef..d8eb410663422f0b7954c449fdabaa06e766bf32 100644
--- a/demos/bernoulli_demo.py
+++ b/demos/bernoulli_demo.py
@@ -52,7 +52,7 @@ if __name__ == '__main__':
     A = ift.create_power_operator(harmonic_space, sqrtpspec)
 
     # Set up a sky operator and instrumental response
-    sky = ift.sigmoid(HT(A))
+    sky = HT(A).ptw("sigmoid")
     GR = ift.GeometryRemover(position_space)
     R = GR
 
diff --git a/demos/getting_started_mf.py b/demos/getting_started_mf.py
index e4ee04cf6408a8b4308f8b3fa227d7bf4937b27c..992b2b1e45cb700d0943a1895d27433f3b64b452 100644
--- a/demos/getting_started_mf.py
+++ b/demos/getting_started_mf.py
@@ -84,7 +84,7 @@ if __name__ == '__main__':
     DC = SingleDomain(correlated_field.target, position_space)
 
     ## Apply a nonlinearity
-    signal = DC @ ift.sigmoid(correlated_field)
+    signal = DC @ correlated_field.ptw("sigmoid")
 
     # Build the line-of-sight response and define signal response
     LOS_starts, LOS_ends = random_los(100) if mode == 0 else radial_los(100)
@@ -170,7 +170,7 @@ if __name__ == '__main__':
     filename_res = filename.format("results")
     plot = ift.Plot()
     plot.add(sc.mean, title="Posterior Mean")
-    plot.add(ift.sqrt(sc.var), title="Posterior Standard Deviation")
+    plot.add(sc.var.ptw("sqrt"), title="Posterior Standard Deviation")
 
     powers1 = [A1.force(s + KL.position) for s in KL.samples]
     powers2 = [A2.force(s + KL.position) for s in KL.samples]