diff --git a/ansi-x963-kdf/src/lib.rs b/ansi-x963-kdf/src/lib.rs
index 9d9213b..dd02419 100644
--- a/ansi-x963-kdf/src/lib.rs
+++ b/ansi-x963-kdf/src/lib.rs
@@ -1,4 +1,5 @@
 #![no_std]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![doc = include_str!("../README.md")]
 
 use core::fmt;
diff --git a/concat-kdf/src/lib.rs b/concat-kdf/src/lib.rs
index b2347f0..cd443f2 100644
--- a/concat-kdf/src/lib.rs
+++ b/concat-kdf/src/lib.rs
@@ -1,4 +1,5 @@
 #![no_std]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![doc = include_str!("../README.md")]
 
 use core::fmt;
diff --git a/hkdf/src/lib.rs b/hkdf/src/lib.rs
index d5bf1ca..9fa49a5 100644
--- a/hkdf/src/lib.rs
+++ b/hkdf/src/lib.rs
@@ -91,7 +91,7 @@
     html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg"
 )]
-#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![forbid(unsafe_code)]
 #![warn(missing_docs, rust_2018_idioms)]
 
diff --git a/kbkdf/src/lib.rs b/kbkdf/src/lib.rs
index 96c3f16..6db54fa 100644
--- a/kbkdf/src/lib.rs
+++ b/kbkdf/src/lib.rs
@@ -1,4 +1,5 @@
 #![no_std]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![doc = include_str!("../README.md")]
 
 use core::{fmt, marker::PhantomData, ops::Mul};