diff --git a/README.md b/README.md
index 22861f7..3dd2f8b 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,21 @@
+> [!IMPORTANT]
+> **This repository is archived and no longer maintained.**
+>
+> These functions are one-line wrappers around the standard library.
+>
+> **Use instead** — standard library:
+> ```go
+> import (
+>     "crypto/sha256"
+>     "fmt"
+> )
+>
+> sum := fmt.Sprintf("%x", sha256.Sum256([]byte(value))) // hex-encoded SHA256
+> ```
+> Use `crypto/sha512` the same way for SHA512.
+
+---
+
 # Go Hash
 
 Simple wrapper functions which take arbitrary string input and return string hashes in hex encoding.