diff --git a/embedded-hal-async/src/lib.rs b/embedded-hal-async/src/lib.rs
index 5fe9168e7..e724207b7 100644
--- a/embedded-hal-async/src/lib.rs
+++ b/embedded-hal-async/src/lib.rs
@@ -1,6 +1,11 @@
 #![doc = include_str!("../README.md")]
 #![warn(missing_docs)]
 #![no_std]
+// disable warning for already-stabilized features.
+// Needed to pass CI, because we deny warnings.
+// We don't immediately remove them to not immediately break older nightlies.
+// When all features are stable, we'll remove them.
+#![allow(stable_features)]
 #![feature(async_fn_in_trait, impl_trait_projections)]
 
 pub mod delay;
diff --git a/embedded-hal-bus/src/lib.rs b/embedded-hal-bus/src/lib.rs
index 6feef548b..a2216a513 100644
--- a/embedded-hal-bus/src/lib.rs
+++ b/embedded-hal-bus/src/lib.rs
@@ -2,6 +2,11 @@
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
+// disable warning for already-stabilized features.
+// Needed to pass CI, because we deny warnings.
+// We don't immediately remove them to not immediately break older nightlies.
+// When all features are stable, we'll remove them.
+#![cfg_attr(feature = "async", stable_features)]
 #![cfg_attr(feature = "async", feature(async_fn_in_trait, impl_trait_projections))]
 
 // needed to prevent defmt macros from breaking, since they emit code that does `defmt::blahblah`.
diff --git a/embedded-io-adapters/src/lib.rs b/embedded-io-adapters/src/lib.rs
index d11316405..533acc1a7 100644
--- a/embedded-io-adapters/src/lib.rs
+++ b/embedded-io-adapters/src/lib.rs
@@ -1,11 +1,19 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
+#![warn(missing_docs)]
+#![doc = include_str!("../README.md")]
+// disable warning for already-stabilized features.
+// Needed to pass CI, because we deny warnings.
+// We don't immediately remove them to not immediately break older nightlies.
+// When all features are stable, we'll remove them.
+#![cfg_attr(
+    any(feature = "tokio-1", feature = "futures-03"),
+    allow(stable_features)
+)]
 #![cfg_attr(
     any(feature = "tokio-1", feature = "futures-03"),
     feature(async_fn_in_trait, impl_trait_projections)
 )]
-#![warn(missing_docs)]
-#![doc = include_str!("../README.md")]
 
 #[cfg(feature = "std")]
 #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
diff --git a/embedded-io-async/src/lib.rs b/embedded-io-async/src/lib.rs
index b38d13abf..a726147d9 100644
--- a/embedded-io-async/src/lib.rs
+++ b/embedded-io-async/src/lib.rs
@@ -1,8 +1,13 @@
-#![feature(async_fn_in_trait, impl_trait_projections)]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![warn(missing_docs)]
 #![doc = include_str!("../README.md")]
+// disable warning for already-stabilized features.
+// Needed to pass CI, because we deny warnings.
+// We don't immediately remove them to not immediately break older nightlies.
+// When all features are stable, we'll remove them.
+#![allow(stable_features)]
+#![feature(async_fn_in_trait, impl_trait_projections)]
 
 #[cfg(feature = "alloc")]
 extern crate alloc;