harmatically sealed relay with flyback diode

Link 1:http://www.drillspot.com/products/152298/Square_D_8501RSD34V53_General_Purpose_Relay link2:http://catalog.weidmueller.com/catalog/Start.do?localeId=en&ObjectID=8533640000
I have weidmuller relay with flyback relay builtin (link 2) and harmatically sealed relay without flyback diode (link 1).I want to remove weidmuller relay and install harmatically sealed relay what is the modification that I do for this relay as it haven't flyback diode

Add a 1N4937 diode across coil. Cathode to positive.