SQL breaks Perl highlighting

gistfile1.txt

#!/var/perl/bin/perl

my $sql =<<'SQL';
insert into foo values (
    -- Add any letter to any of the four words below and the Perl highlighting breaks.
    create,
    update,
    select,
    insert,
)
SQL

my @x = (
    ['missing', 0, {%x, ':x' => undef}],
    ['missing', 0, {%x, ':y' => undef}],
    ['missing', 0, {%x, ':z' => undef}],
);