Type 'uri' not valid in JsonSchema

I'm not sure whether this belongs here or in the Schemata queue, but I'll start here.

I'm getting this exception in the Drupal log:
JsonSchema\Exception\InvalidArgumentException: https://example.com/my/path is an invalid type for uri in JsonSchema\Constraints\TypeConstraint->validateType() (line 214 of /var/www/html/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/TypeConstraint.php).

Like other response validation errors, this happens only if run on an environment configured to run assertions - so should not be affecting production sites.

It appears that a schema used in validateResponse() of ResourceResponseSubscriber.php has a property with a "type" of "uri", which JsonSchema throws an exception about.

Let me know if there is any more info I can give, or testing to do.