diff --git a/demos/wiener_filter_hamiltonian.py b/demos/wiener_filter_hamiltonian.py
index c45689f0dc9b7c8edd316e6d5c8505afdcaa380a..9caae5e7d8c7a532e0ae7ee530e8d2eb3fb6ef13 100644
--- a/demos/wiener_filter_hamiltonian.py
+++ b/demos/wiener_filter_hamiltonian.py
@@ -24,7 +24,7 @@ class WienerFilterEnergy(Energy):
     @property
     def value(self):
         D_inv_x = self.D_inverse_x()
-        H = 0.5 * D_inv_x.vdot(self.position) - self.j.dot(self.position)
+        H = 0.5 * D_inv_x.vdot(self.position) - self.j.vdot(self.position)
         return H.real
 
     @property
diff --git a/nifty/field.py b/nifty/field.py
index 180c918c12a5fa9bab6bc470bbe372ad44bbfd38..fc697139f0d27ab8036385a3c651093602414a8a 100644
--- a/nifty/field.py
+++ b/nifty/field.py
@@ -1100,7 +1100,7 @@ class Field(Loggable, Versionable, object):
             The Lq-norm of the field values.
 
         """
-        return np.sqrt(np.abs(self.dot(x=self)))
+        return np.sqrt(np.abs(self.vdot(x=self)))
 
     def conjugate(self, inplace=False):
         """ Retruns the complex conjugate of the field.