diff --git a/Cargo.toml b/Cargo.toml
index d45766e..56bac5f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ serde = { version = "1", default-features = false, features = ["derive"] }
 serde_bytes = "0.11.12"
 
 [features]
+default = ["heapless-bytes-v0-3"]
 heapless-bytes-v0-3 = ["dep:heapless-bytes-v0-3", "heapless-v0-7"]
 heapless-bytes-v0-4 = ["dep:heapless-bytes-v0-4"]
 heapless-v0-7 = ["dep:heapless-v0-7"]
diff --git a/src/lib.rs b/src/lib.rs
index 45b0c6b..538ad0f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -35,6 +35,7 @@ pub fn cbor_serialize<'a, T: ?Sized + serde::Serialize>(
 }
 
 #[cfg(feature = "heapless-bytes-v0-3")]
+#[deprecated(note = "use `cbor_serialize_to` instead")]
 /// Append serialization of object to existing bytes, returning length of serialized object.
 pub fn cbor_serialize_extending_bytes<T: ?Sized + serde::Serialize, const N: usize>(
     object: &T,
@@ -55,6 +56,7 @@ pub fn cbor_serialize_bytes<T: ?Sized + serde::Serialize, const N: usize>(
     object: &T,
 ) -> Result<heapless_bytes_v0_3::Bytes<N>> {
     let mut data = heapless_bytes_v0_3::Bytes::<N>::new();
+    #[allow(deprecated)]
     cbor_serialize_extending_bytes(object, &mut data)?;
     Ok(data)
 }