diff --git a/libs/earcut/README.md b/libs/earcut/README.md
index 60568bea..b2759705 100644
--- a/libs/earcut/README.md
+++ b/libs/earcut/README.md
@@ -14,6 +14,14 @@ This Zig implementation is a direct port, and should theoretically be equally co
 
 (This repository is a separate copy of the same library in the [main Mach repository](https://github.com/hexops/mach), and is automatically kept in sync, so that anyone can use this library in their own project if they like!)
 
+## Experimental
+
+This is an _experimental_ Mach library, according to our [stability guarantees](https://machengine.org/next/docs/libs/):
+
+> Experimental libraries may have their APIs change without much notice, and you may have to look at recent changes in order to update your code.
+
+[Why this library is not declared stable yet](https://machengine.org/next/docs/libs/experimental/#earcut)
+
 ## Getting started
 
 ### Adding dependency