diff --git a/py_wake/examples/data/hornsrev1.py b/py_wake/examples/data/hornsrev1.py
index e4343b5dd28124a5be9b3fa7c08c45b243ec32b5..a6bc70044e4da24b7988c5fdfcd2e063200c0987 100644
--- a/py_wake/examples/data/hornsrev1.py
+++ b/py_wake/examples/data/hornsrev1.py
@@ -92,14 +92,14 @@ HornsrevV80 = V80
 
 
 class Hornsrev1Site(UniformWeibullSite):
-    def __init__(self):
+    def __init__(self, shear=None):
         f = [3.597152, 3.948682, 5.167395, 7.000154, 8.364547, 6.43485,
              8.643194, 11.77051, 15.15757, 14.73792, 10.01205, 5.165975]
         a = [9.176929, 9.782334, 9.531809, 9.909545, 10.04269, 9.593921,
              9.584007, 10.51499, 11.39895, 11.68746, 11.63732, 10.08803]
         k = [2.392578, 2.447266, 2.412109, 2.591797, 2.755859, 2.595703,
              2.583984, 2.548828, 2.470703, 2.607422, 2.626953, 2.326172]
-        UniformWeibullSite.__init__(self, np.array(f) / np.sum(f), a, k, .1)
+        UniformWeibullSite.__init__(self, np.array(f) / np.sum(f), a, k, .1, shear=shear)
         self.initial_position = np.array([wt_x, wt_y]).T
 
 
diff --git a/py_wake/examples/data/iea37/_iea37.py b/py_wake/examples/data/iea37/_iea37.py
index 13a2cf14a68cdee8dc998854ce96e4ea76674988..4d1c0280d3be5b9a41b4f83524e08ecd733ed606 100644
--- a/py_wake/examples/data/iea37/_iea37.py
+++ b/py_wake/examples/data/iea37/_iea37.py
@@ -16,14 +16,14 @@ class IEA37_WindTurbines(OneTypeWindTurbines):
 
 
 class IEA37Site(UniformSite):
-    def __init__(self, n_wt, ti=.075):
+    def __init__(self, n_wt, ti=.075, shear=None):
         assert n_wt in [9, 16, 36, 64]
 
         from py_wake.examples.data.iea37.iea37_reader import \
             read_iea37_windfarm, read_iea37_windrose
 
         _, wsp, freq = read_iea37_windrose(iea37_path + "iea37-windrose.yaml")
-        UniformSite.__init__(self, freq, ti, ws=wsp)
+        UniformSite.__init__(self, freq, ti, ws=wsp, shear=shear)
         self.initial_position = np.array(read_iea37_windfarm(iea37_path + 'iea37-ex%d.yaml' % n_wt)[:2]).T
 
 
diff --git a/py_wake/examples/data/lillgrund.py b/py_wake/examples/data/lillgrund.py
index 79e69780f09cfb470dc26773d10d998449b9a517..11c1773670b2f494cf13c76a0137c1bde37d4ffe 100644
--- a/py_wake/examples/data/lillgrund.py
+++ b/py_wake/examples/data/lillgrund.py
@@ -90,11 +90,11 @@ LillgrundSWT23 = SWT23
 
 
 class LillgrundSite(UniformWeibullSite):
-    def __init__(self):
+    def __init__(self, shear=None):
         f = [3.8, 4.5, 0.4, 2.8, 8.3, 7.5, 9.9, 14.8, 14.3, 17.0, 12.6, 4.1]
         a = [4.5, 4.7, 3.0, 7.2, 8.8, 8.2, 8.4, 9.5, 9.2, 9.9, 10.3, 6.7]
         k = [1.69, 1.78, 1.82, 1.70, 1.97, 2.49, 2.72, 2.70, 2.88, 3.34, 2.84, 2.23]
-        UniformWeibullSite.__init__(self, f, a, k, .1)
+        UniformWeibullSite.__init__(self, f, a, k, .1, shear=shear)
         self.initial_position = np.array([wt_x, wt_y]).T