How do I change the output encoding of a Scala worksheet

I need to see output with Char codes >255 (UNICODE), but currently I cannot figure out how to configure the worksheet to output (or at least some render conversion internally, to produce output) that works.

For example the following:

val s: Char = '\u8704'

outputs as '?' in the worksheet results pane.  The same applies for any Char code > 255.  I have tried switching the encoding of the worksheet to UTF-32 (and various other possibiltities) but it doesn;t seem to make any difference (I'm guessing this just changes the encoding of the worksheet itself (left pane) but not of its results??