README.md in semantic_logger-4.6.0 vs README.md in semantic_logger-4.6.1

@@ -74,10 +74,10 @@
 - Kafka Appender: gem 'ruby-kafka'
 
 ## V4 Upgrade notes
 
 The following changes need to be made when upgrading to V4:
-- Ruby V2.1 / JRuby V9.1 is now the minimum runtime version.
+- Ruby V2.3 / JRuby V9.1 is now the minimum runtime version.
 - Replace calls to Logger#with_payload with SemanticLogger.named_tagged.
 - Replace calls to Logger#payload with SemanticLogger.named_tags.
 - MongoDB Appender requires Mongo Ruby Client V2 or greater.
 - Appenders now write payload data in a seperate :payload tag instead of mixing them
   directly into the root elements to avoid name clashes.