YAML::Dumper not quoting scalar string "-"

Problem: Getting Perl's `YAML::Dumper` to emit `{key=>"-"}` as `key: "-"` rather than `key: -` I'm processing hashes from database rows, reading them with SOAP and turning them into YAML for consumption by the next stage. The first stage is written in Perl, and generates the YAML using `YAML::Dumper`. Unfortunately, for keys that have a value of `"-"`, the bare hyphen is emitted sans any quoting: ``` $ perl -e 'use YAML;use YAML::Dumper; my $ydumper=YAML::Dumper->new(); print $ydumper->dump({key1=>1,key2=>"-",key3=>3});' --- key1: 1 key2: - key3: 3 ``` The next stage, which reads the above and performs further manipulations on it, is in Ruby. The raw dash causes Ruby's YAML parser to varf: ``` $ ruby -rubygems -ryaml -e 'YAML.load($stdin.read);' # assume the above piped in /usr/share/ruby/vendor_ruby/psych.rb:205:in `parse': (<unknown>): block sequence entries are not allowed in this context at line 3 column 7 (Psych::SyntaxError) from /usr/share/ruby/vendor_ruby/psych.rb:205:in `parse_stream' from /usr/share/ruby/vendor_ruby/psych.rb:153:in `parse' from /usr/share/ruby/vendor_ruby/psych.rb:129:in `load' from -e:1:in `<main>' ``` My question is simple: How can I instruct `YAML::Dumper` to emit the dash as a quoted string? Thanks!