Mapping CLR namespace to custom class problem

[RK62]

I'm just starting with WPF so this is a very basic question.
I try to map XAML namespace to my custom class which is in the same assembly as my window. I however receive the error: "Undefined CLR namespace. The 'clr-namespace' URI refers to a namespace 'myNamespace' that is not included in the assembly."

The XAML code looks like this:

   <Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:custom="clr-namespace:myNamespace"
    Title="MainWindow" Height="367" Width="483">
        
    <Grid ShowGridLines="True">
      
        
    </Grid>
        
</Window>

And my custom class like this

Namespace myNamespace

    Public Class Person

        Private _name As String = "[Insert the name here...]"
        Public Property Name() As String
            Get
                Return _name
            End Get
            Set(ByVal value As String)
                _name = value
            End Set
        End Property
        Private _age As Integer = 30
        Public Property Age As Integer
            Get
                Return _age
            End Get
            Set(ByVal value As Integer)
                _age = value
            End Set
        End Property

        Public Sub New()

        End Sub
    End Class

End Namespace

What goes wrong here?