diff --git a/README.md b/README.md
index dade3eb..77df43c 100644
--- a/README.md
+++ b/README.md
@@ -171,6 +171,8 @@ light-weight, simple, and understandable.
 
 ## Typings
 
+_Please note that TypeScript 4.X is required._
+
 The TypeScript type definitions are in the [types][types-directory] directory.
 
 ## ESLint support