ESLogger logs wrong class name

ESLogger logs wrong class name, method name, line number.

version: 1.0.0

configuration:
  log4j
      conversionPattern: "[%d{ISO8601}][%-5p][%-25c][%C.%M:%L] %m%n"
  slf4j + logback
    <pattern>[%date{ISO8601}][%-5.5level][%-25.25logger][%class{36}.%method:%line] %msg%n</pattern>

ESLogger logs this.(wrong class name!):
  org.elasticsearch.common.logging.log4j.Log4jESLogger.internalInfo:114



ESLogger always logs the class name "Log4jESLogger".
I thought Elasticsearch can avoid it using other log4j/slf4j methods and I changed.