New(?) for qw(...) error

[Paul Makepeace]

I've just had one of my dodgier scripts start bailing on this construction,

$ perl -le 'for $a qw(a b) { print $a }'
a
b
$ perl -le 'for qw(a b) { print }'
Missing $ on loop variable at -e line 1.

This is on 5.8.8; not sure when this kicked in.

P