diff --git a/pyat/at/lattice/elements/magnet_elements.py b/pyat/at/lattice/elements/magnet_elements.py
index ac767d2e2..0c2e78e63 100644
--- a/pyat/at/lattice/elements/magnet_elements.py
+++ b/pyat/at/lattice/elements/magnet_elements.py
@@ -505,7 +505,7 @@ def __init__(
             length:         total length of the wiggler
             wiggle_period:  length must be a multiple of this
             b_max:          peak wiggler field [Tesla]
-            energy:         beam energy [eV]
+            energy:         kept for backwards compatibility but always ignored
             Nstep:          number of integration steps.
             Nmeth:          symplectic integration order: 2 or 4
             Bx:             harmonics for horizontal wiggler: (6, nHharm)
@@ -522,6 +522,13 @@ def __init__(
                 "Wiggler: length / wiggle_period is not an "
                 f"integer. ({length}/{wiggle_period}={n_wiggles})"
             )
+        if energy:
+            warnings.warn(
+                AtWarning(
+                    f"Wiggler: positional argument energy={energy} has been ignored as "
+                    "lattice.Energy is always used instead."
+                )
+            )
         super().__init__(
             family_name,
             length,
@@ -531,7 +538,6 @@ def __init__(
             Nmeth=Nmeth,
             By=By,
             Bx=Bx,
-            Energy=energy,
             **kwargs,
         )
 
diff --git a/pyat/at/lattice/lattice_object.py b/pyat/at/lattice/lattice_object.py
index 77ca383b2..82157c426 100644
--- a/pyat/at/lattice/lattice_object.py
+++ b/pyat/at/lattice/lattice_object.py
@@ -677,9 +677,7 @@ def energy(self) -> float:
     def energy(self, energy: float):
         # Set the Energy attribute of radiating elements
         for elem in self:
-            if isinstance(
-                elem, (elt.RFCavity, elt.Wiggler)
-            ) or elem.PassMethod.endswith("RadPass"):
+            if isinstance(elem, elt.RFCavity) or elem.PassMethod.endswith("RadPass"):
                 elem.Energy = energy
         # Set the energy attribute of the Lattice
         # Use a numpy scalar to allow division by zero
diff --git a/pyat/test/test_basic_elements.py b/pyat/test/test_basic_elements.py
index 1f9ec13d1..5cab9dbbb 100644
--- a/pyat/test/test_basic_elements.py
+++ b/pyat/test/test_basic_elements.py
@@ -552,7 +552,7 @@ def test_wiggler(rin, func):
     periods = 23
     bmax = 1
     by = numpy.array([1, 1, 0, 1, 1, 0], dtype=numpy.float64)
-    c = elements.Wiggler('wiggler', period * periods, period, bmax, 3e9, By=by)
+    c = elements.Wiggler('wiggler', period * periods, period, bmax, By=by)
     assert abs(c.Length - 1.15) < 1e-10
     # Expected value from Matlab AT.
     expected = numpy.array(rin, copy=True)
diff --git a/pyat/test/test_integrators.py b/pyat/test/test_integrators.py
index 5a94bc178..2a896cd99 100644
--- a/pyat/test/test_integrators.py
+++ b/pyat/test/test_integrators.py
@@ -43,7 +43,7 @@ def test_exact_hamiltonian_pass_with_dls_dipole(rin, func):
                          ('GWigSymplecticPass', 'GWigSymplecticRadPass'))
 def test_gwig_symplectic_pass(rin, passmethod, func):
     # Parameters copied from one of the Diamond wigglers.
-    wiggler = elements.Wiggler('w', 1.15, 0.05, 0.8, 3e9)
+    wiggler = elements.Wiggler('w', 1.15, 0.05, 0.8)
     wiggler.PassMethod = passmethod
     func(wiggler, rin)