If you have an use case to validate custom schemas against the one of the JSON schema draft version, here is the code that you can do it. ``` public static final Function> validateAgainstMetaSchema = schema -> { JsonSchemaFactory factory = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V201909); JsonSchema metaSchema = factory.getSchema(getSchemaUri()); return metaSchema.validate(schema).stream() .map((validation) -> new SchemaValidationMessage(validation.getMessage())) .collect(Collectors.toSet()); }; ``` This should now work but does not support all the keywords because the JsonMetaSchema of SpecVersion.VersionFlag.V201909 is lacking these features. You can fix the issue by resolving the vocabularies to a local resource file and re-do the JsonMetaSchema for 2019 based on that.