Issue with cross staff beam

[Stefan Waler]

Hi,

I encountered an issue with accidentals not being taken into account in 
a cross staff beam ... does anybody know a simple workaround?

Thanks!

Stefan

\version "2.12.01"

global = {
        \key c \major
        \time 4/4
}


NotesTest = {

        \clef "bass"

                \relative c'
                {
                        ais8 [ \change Staff=RHStaff dis gis]
                }
}


\score {
        <<
                \new StaffGroup <<
                        \new Staff = "RHStaff" { \skip 1 * 5 }
                        \new Staff = "LHStaff" { \skip 1 * 5 }
                        \context Staff = LHStaff \new Voice << \global 
\NotesTest >>
                >>
        >>
}