README.md in rubocop-sorbet-0.6.1 vs README.md in rubocop-sorbet-0.6.2

@@ -15,9 +15,16 @@
 
 ```ruby
 gem 'rubocop-sorbet', require: false
 ```
 
+Note: in order to use the [Sorbet/SignatureBuildOrder](https://github.com/Shopify/rubocop-sorbet/blob/master/manual/cops_sorbet.md#sorbetsignaturebuildorder) cop autocorrect feature, it is necessary
+to install `unparser` in addition to `rubocop-sorbet`.
+
+```ruby
+gem "unparser", require: false
+```
+
 ## Usage
 
 You need to tell RuboCop to load the Sorbet extension. There are three ways to do this:
 
 ### RuboCop configuration file