Converting data from wcf using reflection Object of type 'System.Int64' cannot be converted to type 'System.Int32'

I'm retrieving a datatable from a wcf function WebMessageFormat = Json and then setting the properties of my data contract using reflection. I'm getting the following error on an int field -

Object of type 'System.Int64' cannot be converted to type 'System.Int32

Can somebody explain what this is and how to address?