How do I make a type of a System.Func with dynamic type arguments

I have

    Type tsomething = /* ... */ ;
    Type comparer = typeof(Func).MakeGenericType(new Type[]{tsomething, tsomething, int});

but the compiler doesn't like the unspecialized Func. Is there a way to spell this out so I can get the generalized type to specialized dynamically.

I can't replace with a directly specialized Func because I don't know my own types at compile time. Reflection.Emit is involved; trying to write typeof(Func<something, something>, int) is impossible.

The exact same construct appears a few lines down with

    il.DeclareLocal(typeof(IEnumerator).MakeGenericType(new Type[]{tsomething}));