diff --git a/bhttp/src/err.rs b/bhttp/src/err.rs
index 19d5455..d9d9b6f 100644
--- a/bhttp/src/err.rs
+++ b/bhttp/src/err.rs
@@ -6,9 +6,6 @@ pub enum Error {
     ConnectUnsupported,
     #[error("a field contained invalid Unicode: {0}")]
     CharacterEncoding(#[from] std::string::FromUtf8Error),
-    #[error("a chunk of data of {0} bytes is too large")]
-    #[cfg(feature = "stream")]
-    ChunkTooLarge(u64),
     #[error("read a response when expecting a request")]
     ExpectedRequest,
     #[error("read a request when expecting a response")]
diff --git a/ohttp/src/lib.rs b/ohttp/src/lib.rs
index 2baeccd..da448d4 100644
--- a/ohttp/src/lib.rs
+++ b/ohttp/src/lib.rs
@@ -92,13 +92,13 @@ pub struct ClientRequest {
 #[cfg(feature = "client")]
 impl ClientRequest {
     /// Construct a `ClientRequest` from a specific `KeyConfig` instance.
-    pub fn from_config(config: &mut KeyConfig) -> Res<Self> {
+    pub fn from_config(config: &KeyConfig) -> Res<Self> {
         // TODO(mt) choose the best config, not just the first.
         let selected = config.select(config.symmetric[0])?;
 
         // Build the info, which contains the message header.
         let info = build_info(config.key_id, selected)?;
-        let hpke = HpkeS::new(selected, &mut config.pk, &info)?;
+        let hpke = HpkeS::new(selected, &config.pk, &info)?;
 
         let header = Vec::from(&info[INFO_REQUEST.len() + 1..]);
         debug_assert_eq!(header.len(), REQUEST_HEADER_LEN);
@@ -108,8 +108,8 @@ impl ClientRequest {
     /// Reads an encoded configuration and constructs a single use client sender.
     /// See `KeyConfig::decode` for the structure details.
     pub fn from_encoded_config(encoded_config: &[u8]) -> Res<Self> {
-        let mut config = KeyConfig::decode(encoded_config)?;
-        Self::from_config(&mut config)
+        let config = KeyConfig::decode(encoded_config)?;
+        Self::from_config(&config)
     }
 
     /// Reads an encoded list of configurations and constructs a single use client sender
diff --git a/ohttp/src/rh/hpke.rs b/ohttp/src/rh/hpke.rs
index 2dcc76d..989dd65 100644
--- a/ohttp/src/rh/hpke.rs
+++ b/ohttp/src/rh/hpke.rs
@@ -11,8 +11,8 @@ use bitcoin_hpke::{
     setup_receiver, setup_sender, Deserializable, OpModeR, OpModeS, Serializable,
 };
 
-use ::rand::thread_rng;
 use log::trace;
+use rand::thread_rng;
 use std::ops::Deref;
 
 /// Configuration for `Hpke`.
@@ -98,7 +98,7 @@ impl PrivateKey {
 
 impl std::fmt::Debug for PrivateKey {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        if let Ok(b) = self.key_data() {
+        if let Ok(_) = self.key_data() {
             write!(f, "PrivateKey [REDACTED]")
         } else {
             write!(f, "Opaque PrivateKey")
@@ -157,7 +157,7 @@ pub struct HpkeS {
 
 impl HpkeS {
     /// Create a new context that uses the KEM mode for sending.
-    pub fn new(config: Config, pk_r: &mut PublicKey, info: &[u8]) -> Res<Self> {
+    pub fn new(config: Config, pk_r: &PublicKey, info: &[u8]) -> Res<Self> {
         let mut csprng = thread_rng();
 
         macro_rules! dispatch_hpkes_new {