diff --git a/simpegEM/Tests/test_FDEM_analytics.py b/simpegEM/Tests/test_FDEM_analytics.py
index c4c29906..3fdafa4d 100644
--- a/simpegEM/Tests/test_FDEM_analytics.py
+++ b/simpegEM/Tests/test_FDEM_analytics.py
@@ -21,7 +21,7 @@ class FDEM_analyticTests(unittest.TestCase):
 
         x = np.linspace(-10,10,5)
         XYZ = Utils.ndgrid(x,np.r_[0],np.r_[0])
-        rxList = EM.FDEM.RxListFDEM(XYZ, 'Ex')
+        rxList = EM.FDEM.RxListFDEM(XYZ, 'ex')
         Tx0 = EM.FDEM.TxFDEM(np.r_[0.,0.,0.], 'VMD', 1e2, rxList)
 
         survey = EM.FDEM.SurveyFDEM([Tx0])
diff --git a/simpegEM/Tests/test_FieldsObject.py b/simpegEM/Tests/test_FieldsObject.py
index 30ef0614..9eebb4a5 100644
--- a/simpegEM/Tests/test_FieldsObject.py
+++ b/simpegEM/Tests/test_FieldsObject.py
@@ -7,7 +7,7 @@ class FieldsTest(unittest.TestCase):
     def setUp(self):
         x = np.linspace(5,10,3)
         XYZ = Utils.ndgrid(x,x,np.r_[0])
-        rxList = EM.FDEM.RxListFDEM(XYZ, 'Ex')
+        rxList = EM.FDEM.RxListFDEM(XYZ, 'ex')
         Tx0 = EM.FDEM.TxFDEM(None, 'VMD', 3, rxList)
         Tx1 = EM.FDEM.TxFDEM(None, 'VMD', 3, rxList)
         Tx2 = EM.FDEM.TxFDEM(None, 'VMD', 2, rxList)