diff --git a/contributed_definitions/NXstress.nxdl.xml b/contributed_definitions/NXstress.nxdl.xml
index 0a4c3fd784..317e117146 100644
--- a/contributed_definitions/NXstress.nxdl.xml
+++ b/contributed_definitions/NXstress.nxdl.xml
@@ -212,7 +212,6 @@
                     <doc>Date calibration was created/added</doc>
                 </field>
             </group>
-            
             <group name="source" type="NXsource" optional="false">
                 <field name="type" type="NX_CHAR" optional="false">
                     <doc>
@@ -237,18 +236,6 @@
                         <item value="X-ray"/>
                     </enumeration>
                 </field>
-                <field name="energy" type="NX_FLOAT" units="NX_ENERGY" optional="true">
-		            <doc>
-			                Source energy. The energy should be provided in keV, but if chosen otherwise, the units must be clearly specified. For storage rings, this would be the particle beam energy.
-			                For X-ray tubes, this would be the excitation voltage.
-
-		            </doc>
-	            </field>
-                <field name="wavelength" type="NX_FLOAT" optional="true">
-                    <doc>
-                        In case of monochromatic radiation, the wavelength used during the experiment. The wavelength should be provided in \ :math:`Å`, but if chosen otherwise, the units must be clearly specified.
-                    </doc>
-                </field>
             </group>
             <group name="DETECTOR" type="NXdetector" minOccurs="1" maxOccurs="unbounded">
                 <doc>Zero or more of these groups describe the detectors used in the experiment.</doc>
@@ -290,7 +277,6 @@
                         In this use case, the efficiency and wavelength arrays must
                         have the same dimensionality.
                     </doc>
-
                     <dimensions rank="2">
                       <dim index="1" value="i" />
                       <dim index="2" value="j" />
@@ -411,6 +397,12 @@
                         Describes how the beam intensity profile in the secondary horizontal direction was determined. Examples of valid entries are: ``measured``, ``theoretical``, ``estimated``, ...  
                     </doc>
                 </field>
+                <field name="incident_energy" type="NX_FLOAT" units="NX_ENERGY" optional="true">
+                    <doc>Incident energy mostly useful for monochromatic beams.</doc>
+                </field>
+                <field name="incident_wavelength" type="NX_FLOAT" units="NX_WAVELENGTH" optional="true">
+                    <doc>Incident wavelength mostly useful for monochromatic beams.</doc>
+                </field>
             </group>
         </group>