ISE: Error when requesting non-existent relationship types on /relationships

Error:
Caught exception in MusicBrainz::Server::Controller::Relationship::LinkType->tree_setup "fake is not a type that has a model at lib/MusicBrainz/Server/Data/Utils.pm line 345."

Stack trace:
line 345 MusicBrainz::Server::Data::Utils
line 42 MusicBrainz::Server::Controller::Relationship::LinkType
line 298 MusicBrainz::Server
line 298 MusicBrainz::Server
line 298 MusicBrainz::Server
line 262 MusicBrainz::Server

Request data:
$VAR1 = {
'query_parameters' => {},
'body_parameters' => {}
};

URL: http://musicbrainz.org/relationships/fake-fake