Error parsing null value into nullable property

I have a wrapper around IDataReader that returns null when the value is DBNull, like this:

public class MyDataReaderWrapper : IDataReader
{
    public object GetValue(int index)
    {
        if (_wrappedDataReader.IsDBNull(index)) return null;
        ...
    }
}

When using the following code Dapper gives "Error parsing column 0(Value=NULL)".

public class Test
{
    public int? Value { get; set; }
}

...

var test = _wrappedDBConnection.Query<Test>("SELECT NULL AS Value FROM DUAL");

I understand that Dapper already deals with DBNull, but my application uses this wrapper so that we don't have to deal with DBNull when using IDataReader directly.

I think Dapper should still work when mapping a null value to a nullable property.

Reproduce the issue with MyDataReaderWrapper, IDataReader.GetValue, the nullable Test.Value property, and the Query call shown in the report. Trace Dapper's column-mapping path for a null object value and compare it with DBNull handling. Done means the query maps the wrapper's null to int? Value without an error, with a regression test covering the example.