XML Serialization class is inaccesible due to its protection level and ILRepack

Question

I am getting the following error:

is inaccessible due to its protection level. Only public types can be processed. at System.Xml.Serialization.TypeDesc.CheckSupported()

on a model class that I am using for deserializing XML. I only get this when I merge my assemblies using ILRepack. If I do not merge the assemblies or exclude the assembly containing the model class it works.