Lua 5.3.0 standalone confused by bare multiline long strings

[Dirk Laurie <dirk.laurie@...>]

$ lua53
Lua 5.3.0 (work2)  Copyright (C) 1994-2014 Lua.org, PUC-Rio
> [[ a ]]
 a
> [[ a
>> ]]
stdin:2: unexpected symbol near '[[ a
]]'
>