diff --git a/tests/test_halos/test_concentrations.py b/tests/test_halos/test_concentrations.py
index 3359d7a..9dd05cc 100644
--- a/tests/test_halos/test_concentrations.py
+++ b/tests/test_halos/test_concentrations.py
@@ -31,14 +31,14 @@ def test_concentration_diemer_joyce(self):
         c = concentration_model.nfw_concentration(m, z)
         npt.assert_equal(c != c_true, True)
 
-        c = concentration_model.nfw_concentration(np.array([10**8]*10), [z]*10)
+        c = concentration_model.nfw_concentration(np.array([10**8]*10), z)
         npt.assert_equal(10, len(c))
 
     def test_concentration_ludlow(self):
 
         m = 10 ** 8
         z = 0.5
-        c_true = 14.246936385951503
+        c_true = 13.602537830392322
         scatter = False
         scatter_amplitude_dex = 0.2
         concentration_model = ConcentrationLudlow(self.astropy, scatter)
@@ -50,7 +50,7 @@ def test_concentration_ludlow(self):
         c = concentration_model.nfw_concentration(m, z)
         npt.assert_equal(c != c_true, True)
 
-        c = concentration_model.nfw_concentration(np.array([10 ** 8] * 10), [z] * 10)
+        c = concentration_model.nfw_concentration(np.array([10 ** 8] * 10), z)
         npt.assert_equal(10, len(c))
 
 
diff --git a/tests/test_preset_models.py b/tests/test_preset_models.py
index ce3ce5e..f31ca0e 100644
--- a/tests/test_preset_models.py
+++ b/tests/test_preset_models.py
@@ -34,7 +34,7 @@ def test_CDM_correlated_structure_only(self):
 
         cdm = CDMCorrelatedStructure(0.5, 1.5)
         _ = cdm.lensing_quantities()
-        
+
     def test_WDM(self):
 
         wdm = WDM(0.5, 1.5, 8.0)