It looks like these two commits are backwards: Addition of `binary` property: https://github.com/swagger-api/swagger-core/commit/a18409eb69d9c69435bb2f0bbec7b2540b46616d Addition of `byte` property: https://github.com/swagger-api/swagger-core/commit/4e7a8014d14a8d0dd54f31f825858ae072be1061