diff --git a/crates/derive/src/lib.rs b/crates/derive/src/lib.rs
index c7efe25..772c6f4 100644
--- a/crates/derive/src/lib.rs
+++ b/crates/derive/src/lib.rs
@@ -141,15 +141,11 @@ struct TypeTag {
 
 impl Parse for TypeTag {
     fn parse(input: ParseStream) -> Result<Self> {
-        let mut inner = None;
         let content;
         parenthesized!(content in input);
         let punctuated = Punctuated::<syn::LitStr, Comma>::parse_terminated(&content)?;
 
-        for pair in punctuated.pairs() {
-            inner = Some(pair.into_value());
-            break;
-        }
+        let inner = punctuated.pairs().map(|x| x.into_value()).next();
 
         Ok(TypeTag {
             inner: inner.unwrap().to_owned(),
diff --git a/src/builder.rs b/src/builder.rs
index 5d6740f..553fc94 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -9,12 +9,21 @@ use tokio::sync::Mutex;
 use crate::{
     envelop::TypeTag,
     error::{Error, StdSyncSendError},
-    receiver::{Receiver, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        BusPollerCallback, Receiver, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers, AsyncBatchHandler, AsyncBatchSynchronizedHandler, AsyncHandler,
     AsyncSynchronizedHandler, BatchHandler, BatchSynchronizedHandler, Bus, BusInner, Handler,
     IntoBoxedMessage, Message, Relay, SynchronizedHandler, Untyped,
 };
 
+type MessageDeserializerCallback = Box<
+    dyn Fn(&mut dyn erased_serde::Deserializer<'_>) -> Result<Box<dyn Message>, Error>
+        + Send
+        + Sync,
+>;
+
 pub trait ReceiverSubscriberBuilder<T, M, R, E>:
     SendUntypedReceiver + SendTypedReceiver<M> + ReciveTypedReceiver<R, E>
 where
@@ -25,14 +34,7 @@ where
 {
     type Config: Default;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    )
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback)
     where
         Self: Sized;
 }
@@ -47,14 +49,14 @@ pub struct RegisterEntry<K, T, F, P, B> {
     builder: F,
     poller: P,
     receivers: HashMap<TypeTag, Receiver>,
-    pollers: Vec<Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>>,
+    pollers: Vec<BusPollerCallback>,
     _m: PhantomData<(K, T)>,
 }
 
 impl<K, T: 'static, F, P, B> RegisterEntry<K, T, F, P, B>
 where
     F: FnMut(&mut B, TypeTag, Receiver),
-    P: FnMut(&mut B, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>),
+    P: FnMut(&mut B, BusPollerCallback),
 {
     pub fn done(mut self) -> B {
         for (tid, v) in self.receivers {
@@ -209,11 +211,7 @@ impl<T, F, P, B> RegisterEntry<SyncEntry, T, F, P, B> {
 }
 
 pub struct MessageTypeDescriptor {
-    de: Box<
-        dyn Fn(&mut dyn erased_serde::Deserializer<'_>) -> Result<Box<dyn Message>, Error>
-            + Send
-            + Sync,
-    >,
+    de: MessageDeserializerCallback,
 }
 
 impl MessageTypeDescriptor {
@@ -226,10 +224,11 @@ impl MessageTypeDescriptor {
     }
 }
 
+#[derive(Default)]
 pub struct Module {
     message_types: HashMap<TypeTag, MessageTypeDescriptor>,
     receivers: HashMap<TypeTag, SmallVec<[Receiver; 4]>>,
-    pollings: Vec<Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>>,
+    pollings: Vec<BusPollerCallback>,
 }
 
 impl Module {
diff --git a/src/envelop.rs b/src/envelop.rs
index 6408b2e..cc6c7da 100644
--- a/src/envelop.rs
+++ b/src/envelop.rs
@@ -136,11 +136,11 @@ impl Message for () {
             return false;
         };
 
-        into.replace(self.clone());
+        into.replace(());
         true
     }
     fn try_clone_boxed(&self) -> Option<Box<dyn Message>> {
-        Some(Box::new(self.clone()))
+        Some(Box::new(()))
     }
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index ccdf763..11a3a1a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -95,7 +95,7 @@ impl Bus {
     }
 
     pub(crate) fn init(&self) {
-        for (_, rs) in &self.inner.receivers {
+        for rs in self.inner.receivers.values() {
             for r in rs {
                 r.init(self).unwrap();
             }
@@ -103,7 +103,7 @@ impl Bus {
     }
 
     pub async fn ready(&self) {
-        for (_, rs) in &self.inner.receivers {
+        for rs in self.inner.receivers.values() {
             for r in rs {
                 r.ready().await;
             }
@@ -114,7 +114,7 @@ impl Bus {
         let _handle = self.inner.maintain.lock().await;
         self.inner.closed.store(true, Ordering::SeqCst);
 
-        for (_, rs) in &self.inner.receivers {
+        for rs in self.inner.receivers.values() {
             for r in rs {
                 let err = tokio::time::timeout(Duration::from_secs(20), r.close(self)).await;
 
@@ -133,7 +133,7 @@ impl Bus {
         for _ in 0..fuse_count {
             iters += 1;
             let mut flushed = false;
-            for (_, rs) in &self.inner.receivers {
+            for rs in self.inner.receivers.values() {
                 for r in rs {
                     if r.need_flush() {
                         flushed = true;
@@ -163,7 +163,7 @@ impl Bus {
         self.flush().await;
         let _handle = self.inner.maintain.lock().await;
 
-        for (_, rs) in &self.inner.receivers {
+        for rs in self.inner.receivers.values() {
             for r in rs {
                 r.sync(self).await;
             }
@@ -598,7 +598,7 @@ impl Bus {
             .inner
             .message_types
             .get(&tt)
-            .ok_or_else(|| Error::TypeTagNotRegistered(tt))?;
+            .ok_or(Error::TypeTagNotRegistered(tt))?;
 
         md.deserialize_boxed(de)
             .map_err(|err| err.specify::<Box<dyn Message>>())
diff --git a/src/receiver.rs b/src/receiver.rs
index 8d5db58..1ee1b6e 100644
--- a/src/receiver.rs
+++ b/src/receiver.rs
@@ -1,5 +1,6 @@
 use crate::relay::RelayWrapper;
 use crate::stats::Stats;
+use crate::Untyped;
 use crate::{
     envelop::{IntoBoxedMessage, TypeTag},
     error::{GenericError, SendError, StdSyncSendError},
@@ -19,6 +20,9 @@ use futures::{Future, FutureExt, StreamExt};
 use std::{borrow::Cow, sync::Arc};
 use tokio::sync::{oneshot, Notify};
 
+pub type BusPollerCallback = Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>;
+pub type UntypedPollerCallback = Box<dyn FnOnce(Untyped) -> BusPollerCallback>;
+
 struct SlabCfg;
 impl sharded_slab::Config for SlabCfg {
     const RESERVED_BITS: usize = 1;
@@ -74,9 +78,7 @@ pub trait WrapperErrorTypeOnly<E: StdSyncSendError>: Send + Sync {
 }
 
 pub trait WrapperReturnTypeAndError<R: Message, E: StdSyncSendError>: Send + Sync {
-    fn start_polling_events(
-        self: Arc<Self>,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>;
+    fn start_polling_events(self: Arc<Self>) -> BusPollerCallback;
     fn add_response_listener(
         &self,
         listener: oneshot::Sender<Result<R, Error<(), E>>>,
@@ -123,9 +125,7 @@ pub trait ReceiverTrait: TypeTagAccept + Send + Sync {
     fn reserve_notify(&self, tt: &TypeTag) -> Arc<Notify>;
     fn increment_processing(&self, tt: &TypeTag);
 
-    fn start_polling(
-        self: Arc<Self>,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>;
+    fn start_polling(self: Arc<Self>) -> BusPollerCallback;
 }
 
 pub trait ReceiverPollerBuilder {
@@ -181,9 +181,7 @@ where
     E: StdSyncSendError,
     S: SendUntypedReceiver + ReciveTypedReceiver<R, E> + Send + Sync + 'static,
 {
-    fn start_polling_events(
-        self: Arc<Self>,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>> {
+    fn start_polling_events(self: Arc<Self>) -> BusPollerCallback {
         Box::new(move |_| {
             Box::pin(async move {
                 let this = self.clone();
@@ -253,7 +251,7 @@ where
         Ok(self
             .waiters
             .insert(Waiter::WithErrorType(listener))
-            .ok_or_else(|| Error::AddListenerError)? as _)
+            .ok_or(Error::AddListenerError)? as _)
     }
 
     fn response(&self, mid: u64, resp: Result<R, Error<(), E>>) -> Result<(), Error> {
@@ -291,7 +289,7 @@ where
         Ok(self
             .waiters
             .insert(Waiter::WithoutErrorType(listener))
-            .ok_or_else(|| Error::AddListenerError)? as _)
+            .ok_or(Error::AddListenerError)? as _)
     }
 }
 
@@ -309,7 +307,7 @@ where
         Ok(self
             .waiters
             .insert(Waiter::BoxedWithError(listener))
-            .ok_or_else(|| Error::AddListenerError)? as _)
+            .ok_or(Error::AddListenerError)? as _)
     }
 }
 
@@ -372,8 +370,8 @@ where
             .downcast::<M>()
             .map_err(|_| Error::MessageCastError)?;
 
-        Ok(SendTypedReceiver::send(&self.inner, mid, *boxed, req, bus)
-            .map_err(|err| Error::from(err.into_boxed()))?)
+        SendTypedReceiver::send(&self.inner, mid, *boxed, req, bus)
+            .map_err(|err| Error::from(err.into_boxed()))
     }
 
     fn stats(&self) -> Stats {
@@ -417,7 +415,7 @@ where
         Ok(self
             .waiters
             .insert(Waiter::Boxed(listener))
-            .ok_or_else(|| Error::AddListenerError)? as _)
+            .ok_or(Error::AddListenerError)? as _)
     }
 
     fn ready_notify(&self) -> &Notify {
@@ -465,9 +463,7 @@ where
         self.context.response.clone()
     }
 
-    fn start_polling(
-        self: Arc<Self>,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>> {
+    fn start_polling(self: Arc<Self>) -> BusPollerCallback {
         self.start_polling_events()
     }
 
@@ -840,9 +836,7 @@ impl Receiver {
     }
 
     #[inline]
-    pub fn start_polling(
-        &self,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>> {
+    pub fn start_polling(&self) -> BusPollerCallback {
         self.inner.clone().start_polling()
     }
 
diff --git a/src/receivers/buffer_unordered/async.rs b/src/receivers/buffer_unordered/async.rs
index 1e55b50..0c66ef5 100644
--- a/src/receivers/buffer_unordered/async.rs
+++ b/src/receivers/buffer_unordered/async.rs
@@ -10,7 +10,10 @@ use crate::{
     buffer_unordered_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     AsyncHandler, Bus, Message, Untyped,
 };
@@ -56,14 +59,7 @@ where
 {
     type Config = BufferUnorderedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let stats = Arc::new(BufferUnorderedStats {
             buffer: AtomicU64::new(0),
             buffer_total: AtomicU64::new(cfg.buffer_size as _),
diff --git a/src/receivers/buffer_unordered/mod.rs b/src/receivers/buffer_unordered/mod.rs
index 2fc0f77..9b35051 100644
--- a/src/receivers/buffer_unordered/mod.rs
+++ b/src/receivers/buffer_unordered/mod.rs
@@ -52,6 +52,7 @@ macro_rules! buffer_unordered_poller_macro {
             while let Some(msg) = rx.recv().await {
                 match msg {
                     Request::Request(mid, msg, _req) => {
+                        #[allow(clippy::redundant_closure_call)]
                         let _ = ($st1)(
                             mid,
                             msg,
@@ -74,6 +75,8 @@ macro_rules! buffer_unordered_poller_macro {
 
                     Request::Action(Action::Sync) => {
                         let lock = semaphore.acquire_many(cfg.max_parallel as _).await;
+
+                        #[allow(clippy::redundant_closure_call)]
                         let resp = ($st2)(bus.clone(), ut.clone()).await;
                         drop(lock);
 
diff --git a/src/receivers/buffer_unordered/sync.rs b/src/receivers/buffer_unordered/sync.rs
index fbce53c..03bef8c 100644
--- a/src/receivers/buffer_unordered/sync.rs
+++ b/src/receivers/buffer_unordered/sync.rs
@@ -11,7 +11,10 @@ use crate::{
     buffer_unordered_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     Bus, Handler, Message, Untyped,
 };
@@ -59,14 +62,7 @@ where
 {
     type Config = BufferUnorderedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let stats = Arc::new(BufferUnorderedStats {
             buffer: AtomicU64::new(0),
             buffer_total: AtomicU64::new(cfg.buffer_size as _),
diff --git a/src/receivers/buffer_unordered_batched/async.rs b/src/receivers/buffer_unordered_batched/async.rs
index 742eb71..b4c6dd8 100644
--- a/src/receivers/buffer_unordered_batched/async.rs
+++ b/src/receivers/buffer_unordered_batched/async.rs
@@ -10,7 +10,10 @@ use crate::{
     buffer_unordered_batch_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     AsyncBatchHandler, Bus, Message, Untyped,
 };
@@ -55,14 +58,7 @@ where
 {
     type Config = BufferUnorderedBatchedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let stats = Arc::new(BufferUnorderedBatchedStats {
             buffer: AtomicU64::new(0),
             buffer_total: AtomicU64::new(cfg.buffer_size as _),
diff --git a/src/receivers/buffer_unordered_batched/mod.rs b/src/receivers/buffer_unordered_batched/mod.rs
index 3c2e76e..bbe24f9 100644
--- a/src/receivers/buffer_unordered_batched/mod.rs
+++ b/src/receivers/buffer_unordered_batched/mod.rs
@@ -74,6 +74,7 @@ macro_rules! buffer_unordered_batch_poller_macro {
                             let buffer_mid_clone = buffer_mid.drain(..).collect::<Vec<_>>();
                             let buffer_clone = buffer.drain(..).collect();
 
+                            #[allow(clippy::redundant_closure_call)]
                             let _ =
                                 ($st1)(buffer_mid_clone, buffer_clone, bus, ut, task_permit, stx);
                         }
@@ -92,6 +93,7 @@ macro_rules! buffer_unordered_batch_poller_macro {
                             let buffer_clone = buffer.drain(..).collect();
                             let task_permit = semaphore.clone().acquire_owned().await;
 
+                            #[allow(clippy::redundant_closure_call)]
                             let _ =
                                 ($st1)(buffer_mid_clone, buffer_clone, bus, ut, task_permit, stx);
                         }
@@ -102,6 +104,8 @@ macro_rules! buffer_unordered_batch_poller_macro {
 
                     Request::Action(Action::Sync) => {
                         let lock = semaphore.acquire_many(cfg.max_parallel as _).await;
+
+                        #[allow(clippy::redundant_closure_call)]
                         let resp = ($st2)(bus.clone(), ut.clone()).await;
                         drop(lock);
 
diff --git a/src/receivers/buffer_unordered_batched/sync.rs b/src/receivers/buffer_unordered_batched/sync.rs
index 0fdd262..3b62f26 100644
--- a/src/receivers/buffer_unordered_batched/sync.rs
+++ b/src/receivers/buffer_unordered_batched/sync.rs
@@ -11,7 +11,10 @@ use crate::{
     buffer_unordered_batch_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     BatchHandler, Bus, Message, Untyped,
 };
@@ -61,14 +64,7 @@ where
 {
     type Config = BufferUnorderedBatchedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let stats = Arc::new(BufferUnorderedBatchedStats {
             buffer: AtomicU64::new(0),
             buffer_total: AtomicU64::new(cfg.buffer_size as _),
diff --git a/src/receivers/synchronize_batched/async.rs b/src/receivers/synchronize_batched/async.rs
index 520a00f..8e9c053 100644
--- a/src/receivers/synchronize_batched/async.rs
+++ b/src/receivers/synchronize_batched/async.rs
@@ -5,7 +5,10 @@ use crate::{
     batch_synchronized_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     AsyncBatchSynchronizedHandler, Bus, Message, Untyped,
 };
@@ -49,14 +52,7 @@ where
 {
     type Config = SynchronizedBatchedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let (stx, srx) = mpsc::unbounded_channel();
         let (tx, rx) = mpsc::unbounded_channel();
 
diff --git a/src/receivers/synchronize_batched/mod.rs b/src/receivers/synchronize_batched/mod.rs
index d84fc58..7ce55b8 100644
--- a/src/receivers/synchronize_batched/mod.rs
+++ b/src/receivers/synchronize_batched/mod.rs
@@ -67,6 +67,7 @@ macro_rules! batch_synchronized_poller_macro {
                             let buffer_mid_clone = buffer_mid.drain(..).collect::<Vec<_>>();
                             let buffer_clone = buffer.drain(..).collect();
 
+                            #[allow(clippy::redundant_closure_call)]
                             let _ = ($st1)(buffer_mid_clone, buffer_clone, bus, ut, stx);
                         }
                     }
@@ -83,6 +84,7 @@ macro_rules! batch_synchronized_poller_macro {
                             let buffer_mid_clone = buffer_mid.drain(..).collect::<Vec<_>>();
                             let buffer_clone = buffer.drain(..).collect();
 
+                            #[allow(clippy::redundant_closure_call)]
                             let _ = ($st1)(buffer_mid_clone, buffer_clone, bus, ut, stx);
                         }
 
@@ -90,6 +92,7 @@ macro_rules! batch_synchronized_poller_macro {
                     }
 
                     Request::Action(Action::Sync) => {
+                        #[allow(clippy::redundant_closure_call)]
                         let resp = ($st2)(bus.clone(), ut.clone()).await;
                         stx.send(Event::Synchronized(resp.map_err(Error::Other)))
                             .unwrap();
diff --git a/src/receivers/synchronize_batched/sync.rs b/src/receivers/synchronize_batched/sync.rs
index 8bcce54..9042268 100644
--- a/src/receivers/synchronize_batched/sync.rs
+++ b/src/receivers/synchronize_batched/sync.rs
@@ -4,7 +4,10 @@ use crate::{
     batch_synchronized_poller_macro,
     builder::ReceiverSubscriberBuilder,
     error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receiver::{
+        Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver,
+        UntypedPollerCallback,
+    },
     receivers::Request,
     BatchSynchronizedHandler, Bus, Message, Untyped,
 };
@@ -53,14 +56,7 @@ where
 {
     type Config = SynchronizedBatchedConfig;
 
-    fn build(
-        cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let (stx, srx) = mpsc::unbounded_channel();
         let (tx, rx) = mpsc::unbounded_channel();
 
diff --git a/src/receivers/synchronized/async.rs b/src/receivers/synchronized/async.rs
index 65c5d69..cb86ea3 100644
--- a/src/receivers/synchronized/async.rs
+++ b/src/receivers/synchronized/async.rs
@@ -1,6 +1,6 @@
 use std::{pin::Pin, sync::Arc};
 
-use crate::synchronized_poller_macro;
+use crate::{receiver::UntypedPollerCallback, synchronized_poller_macro};
 use futures::{Future, Stream};
 
 use super::SynchronizedConfig;
@@ -52,14 +52,7 @@ where
 {
     type Config = SynchronizedConfig;
 
-    fn build(
-        _cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(_cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let (stx, srx) = mpsc::unbounded_channel();
         let (tx, rx) = mpsc::unbounded_channel();
 
diff --git a/src/receivers/synchronized/mod.rs b/src/receivers/synchronized/mod.rs
index a098530..f2ec28a 100644
--- a/src/receivers/synchronized/mod.rs
+++ b/src/receivers/synchronized/mod.rs
@@ -42,7 +42,9 @@ macro_rules! synchronized_poller_macro {
 
             while let Some(msg) = rx.recv().await {
                 match msg {
-                    Request::Request(mid, msg, _req) => {
+                    Request::Request(mid, msg, _req) =>
+                    {
+                        #[allow(clippy::redundant_closure_call)]
                         ($st1)(mid, msg, bus.clone(), ut.clone(), stx.clone())
                             .await
                             .unwrap()
@@ -57,6 +59,7 @@ macro_rules! synchronized_poller_macro {
                         stx.send(Event::Flushed).unwrap();
                     }
                     Request::Action(Action::Sync) => {
+                        #[allow(clippy::redundant_closure_call)]
                         let resp = ($st2)(bus.clone(), ut.clone()).await;
                         stx.send(Event::Synchronized(resp.map_err(Error::Other)))
                             .unwrap();
diff --git a/src/receivers/synchronized/sync.rs b/src/receivers/synchronized/sync.rs
index e59b340..b44e788 100644
--- a/src/receivers/synchronized/sync.rs
+++ b/src/receivers/synchronized/sync.rs
@@ -1,6 +1,6 @@
 use std::{pin::Pin, sync::Arc};
 
-use crate::synchronized_poller_macro;
+use crate::{receiver::UntypedPollerCallback, synchronized_poller_macro};
 use futures::{executor::block_on, Future, Stream};
 
 use super::SynchronizedConfig;
@@ -53,14 +53,7 @@ where
 {
     type Config = SynchronizedConfig;
 
-    fn build(
-        _cfg: Self::Config,
-    ) -> (
-        Self,
-        Box<
-            dyn FnOnce(Untyped) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
-        >,
-    ) {
+    fn build(_cfg: Self::Config) -> (Self, UntypedPollerCallback) {
         let (stx, srx) = mpsc::unbounded_channel();
         let (tx, rx) = mpsc::unbounded_channel();
 
diff --git a/src/relay.rs b/src/relay.rs
index b102251..d4a6aba 100644
--- a/src/relay.rs
+++ b/src/relay.rs
@@ -1,18 +1,15 @@
 use crate::{
     error::Error,
     receiver::{
-        Action, AnyReceiver, AnyWrapperRef, PermitDrop, ReceiverTrait, SendUntypedReceiver,
-        TypeTagAccept,
+        Action, AnyReceiver, AnyWrapperRef, BusPollerCallback, PermitDrop, ReceiverTrait,
+        SendUntypedReceiver, TypeTagAccept,
     },
     stats::Stats,
     Bus, Event, Message, Permit, ReciveUntypedReceiver, TypeTag,
 };
-use core::{
-    pin::Pin,
-    sync::atomic::{AtomicBool, AtomicU64, Ordering},
-};
+use core::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use dashmap::DashMap;
-use futures::{pin_mut, Future, StreamExt};
+use futures::{pin_mut, StreamExt};
 use std::sync::Arc;
 use tokio::sync::{oneshot, Notify};
 
@@ -159,7 +156,7 @@ where
         Ok(self
             .waiters
             .insert(listener)
-            .ok_or_else(|| Error::AddListenerError)? as _)
+            .ok_or(Error::AddListenerError)? as _)
     }
 
     fn try_reserve(&self, tt: &TypeTag) -> Option<Permit> {
@@ -223,9 +220,7 @@ where
             .map(|r| r.processing.fetch_add(1, Ordering::SeqCst));
     }
 
-    fn start_polling(
-        self: Arc<Self>,
-    ) -> Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>> {
+    fn start_polling(self: Arc<Self>) -> BusPollerCallback {
         Box::new(move |_| {
             Box::pin(async move {
                 let this = self.clone();
diff --git a/tests/test_relay.rs b/tests/test_relay.rs
index 17c92d6..c3bf667 100644
--- a/tests/test_relay.rs
+++ b/tests/test_relay.rs
@@ -45,9 +45,14 @@ impl AsyncHandler<Msg<i32>> for TmpReceiver {
     }
 }
 
+pub type TestRelayRxChannelCell =
+    Mutex<Option<mpsc::UnboundedReceiver<Event<Box<dyn Message>, GenericError>>>>;
+pub type TestRelayRxStream =
+    Pin<Box<dyn Stream<Item = Event<Box<dyn Message>, error::GenericError>> + Send>>;
+
 pub struct TestRelay {
     stx: mpsc::UnboundedSender<Event<Box<dyn Message>, GenericError>>,
-    srx: Mutex<Option<mpsc::UnboundedReceiver<Event<Box<dyn Message>, GenericError>>>>,
+    srx: TestRelayRxChannelCell,
 }
 
 impl TypeTagAccept for TestRelay {
@@ -104,9 +109,7 @@ impl TypeTagAccept for TestRelay {
             &Msg::<i32>::type_tag_(),
             &Msg::<i64>::type_tag_(),
             &Error::type_tag_(),
-        ) {
-            return;
-        }
+        ) {}
     }
 }
 
@@ -155,7 +158,7 @@ impl SendUntypedReceiver for TestRelay {
 }
 
 impl ReciveUntypedReceiver for TestRelay {
-    type Stream = Pin<Box<dyn Stream<Item = Event<Box<dyn Message>, error::GenericError>> + Send>>;
+    type Stream = TestRelayRxStream;
 
     fn event_stream(&self) -> Self::Stream {
         let mut rx = self.srx.lock().take().unwrap();
diff --git a/tests/test_req_resp.rs b/tests/test_req_resp.rs
index 538b7f3..f916e3c 100644
--- a/tests/test_req_resp.rs
+++ b/tests/test_req_resp.rs
@@ -229,7 +229,7 @@ async fn test() {
         .await
         .unwrap();
 
-    assert_eq!(we_res.0, 1633.0f64);
+    assert!((we_res.0 - 1633.0f64).abs() < f64::EPSILON);
 
     let boxed_res = b
         .request_boxed(Box::new(MsgF64(1000.)), Default::default())
@@ -237,7 +237,8 @@ async fn test() {
         .unwrap();
 
     let val = boxed_res.as_any_ref().downcast_ref::<MsgF64>().unwrap().0;
-    assert_eq!(val, 1633.0);
+
+    assert!((val - 1633.0f64).abs() < f64::EPSILON);
 
     b.flush().await;
     b.close().await;
diff --git a/tests/test_shared.rs b/tests/test_shared.rs
index 773e011..c4808ac 100644
--- a/tests/test_shared.rs
+++ b/tests/test_shared.rs
@@ -87,6 +87,6 @@ async fn test_shared() {
     b.close().await;
     poller.await;
 
-    assert_eq!(ctx.sync1.load(Ordering::Relaxed), true);
-    assert_eq!(ctx.sync2.load(Ordering::Relaxed), false);
+    assert!(ctx.sync1.load(Ordering::Relaxed));
+    assert!(!ctx.sync2.load(Ordering::Relaxed));
 }