How to have a class have a UDT as property?

[jeroen79]

I want a class to have a property taht returns and takes a UDT.
But it won't work.

My code:

'Module:
Public Type tA
    B As Long
End Type
 
'Class:
Private vA As tA
 
Public Property Get A() As tA
    A = vA
End Property
Public Property Let A(val As tA)
    vA = val
End Property
 
'Form:
Private C As Class1
 
Private Sub Form_Load()
    Set C = New Class1
    C.A.B = 1
End Sub

This gives a compiler error:

Only public user defined types defined in public object modules can be used as parameters or return types for public procedures of class modules or as fields of public user defined types

What am I doing wrong?
How do I make a public object module?