diff --git a/docs/v3-to-v4.md b/docs/v3-to-v4.md
index 0bf0d269b90..577c04835d1 100644
--- a/docs/v3-to-v4.md
+++ b/docs/v3-to-v4.md
@@ -4,6 +4,7 @@ Version 4 of Node Redis is a major refactor. While we have tried to maintain bac
 
 ## All of the Breaking Changes
 
+If using Typescript set the target to ES2015 (ES6) or higher, ES5 and below are not supported due to the usage of `private` class functions.
 See the [Change Log](../CHANGELOG.md).
 
 ### Promises