diff --git a/README.md b/README.md
index c4d0eed..36d8d21 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 [![Yes, this bizarre 863-byte Bash JSON parser is actually tested.](https://github.com/memotype/bj.sh/actions/workflows/verify.yml/badge.svg)](https://github.com/memotype/bj.sh/actions/workflows/verify.yml)
 
 bj.sh is a pure GNU Bash library for parsing JSON data.
+It requires GNU Bash 4.1 or newer.
 
 bj.sh is meant to be run as a script, sourced as a library, or copied directly
 in to your script for maximum flexibility. Great for embedded systems, build