Hi Hans, the \autoinsertnextspace command fails when it gets a \par token. \starttext \dontleavehmode\autoinsertnextspace\par \stoptext The error disappears when you pass the argument to lua as a long string: \def\spac_spaces_auto_insert_next - {\ctxcommand{autonextspace("\meaning\nexttoken")}} % todo, just consult nexttoken at the lua end + {\ctxcommand{autonextspace(\!!bs\meaning\nexttoken\!!es)}} % todo, just consult nexttoken at the lua end Wolfgang