https://github.com/json-schema-org/JSON-Schema-Test-Suite/blob/9ce7b4cf804f1551c20ca33d435bdc22785f39d6/tests/draft6/ref.json#L229 According to http://json-schema.org/latest/json-schema-core.html#rfc.section.8 > All other properties in a "$ref" object MUST be ignored. So should validator just ignore "definitions" in schema?