diff --git a/viz-core/Cargo.toml b/viz-core/Cargo.toml
index b740ef11..3b82b253 100644
--- a/viz-core/Cargo.toml
+++ b/viz-core/Cargo.toml
@@ -99,6 +99,7 @@ tokio = { workspace = true, optional = true }
 tokio-tungstenite = { workspace = true, optional = true }
 tokio-stream = { workspace = true, optional = true }
 tokio-util = { workspace = true, optional = true }
+sync_wrapper = { version = "0.1.2", git = "https://github.com/fundon/sync_wrapper.git", rev = "e2ce8d8" }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }
diff --git a/viz-core/src/body.rs b/viz-core/src/body.rs
index d00a40ef..2727c13e 100644
--- a/viz-core/src/body.rs
+++ b/viz-core/src/body.rs
@@ -4,8 +4,9 @@ use std::{
 };
 
 use futures_util::{Stream, TryStreamExt};
-use http_body_util::{combinators::BoxBody, BodyExt, Full, StreamBody};
+use http_body_util::{combinators::UnsyncBoxBody, BodyExt, Full, StreamBody};
 use hyper::body::{Body, Frame, Incoming, SizeHint};
+use sync_wrapper::SyncWrapper;
 
 use crate::{BoxError, Bytes, Error, Result};
 
@@ -123,26 +124,26 @@ pub enum OutgoingBody<D = Bytes> {
     /// A body that consists of a single chunk.
     Full(Full<D>),
     /// A boxed [`Body`] trait object.
-    Boxed(BoxBody<D, Error>),
+    Boxed(SyncWrapper<UnsyncBoxBody<D, Error>>),
 }
 
 impl OutgoingBody {
     /// A body created from a [`Stream`].
-    pub fn streaming<S, D, E>(stream: S) -> Self
+    pub fn stream<S, D, E>(stream: S) -> Self
     where
-        S: Stream<Item = Result<D, E>> + Send + Sync + 'static,
+        S: Stream<Item = Result<D, E>> + Send + 'static,
         D: Into<Bytes> + 'static,
         E: Into<Error> + 'static,
     {
-        Self::Boxed(
+        Self::Boxed(SyncWrapper::new(
             StreamBody::new(
                 stream
                     .map_ok(Into::into)
                     .map_ok(Frame::data)
                     .map_err(Into::into),
             )
-            .boxed(),
-        )
+            .boxed_unsync(),
+        ))
     }
 }
 
@@ -164,7 +165,7 @@ impl Body for OutgoingBody {
         match self.get_mut() {
             Self::Empty => Poll::Ready(None),
             Self::Full(full) => Pin::new(full).poll_frame(cx).map_err(Error::from),
-            Self::Boxed(body) => Pin::new(body).poll_frame(cx),
+            Self::Boxed(body) => Pin::new(body.get_mut()).poll_frame(cx),
         }
     }
 
@@ -173,7 +174,7 @@ impl Body for OutgoingBody {
         match self {
             Self::Empty => true,
             Self::Full(full) => full.is_end_stream(),
-            Self::Boxed(body) => body.is_end_stream(),
+            Self::Boxed(wrapper) => wrapper.get_ref().is_end_stream(),
         }
     }
 
@@ -182,7 +183,7 @@ impl Body for OutgoingBody {
         match self {
             Self::Empty => SizeHint::with_exact(0),
             Self::Full(full) => full.size_hint(),
-            Self::Boxed(body) => body.size_hint(),
+            Self::Boxed(wrapper) => wrapper.get_ref().size_hint(),
         }
     }
 }
@@ -197,7 +198,7 @@ impl Stream for OutgoingBody {
             Self::Full(full) => Pin::new(full)
                 .poll_frame(cx)
                 .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?,
-            Self::Boxed(body) => Pin::new(body)
+            Self::Boxed(wrapper) => Pin::new(wrapper.get_mut())
                 .poll_frame(cx)
                 .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?,
         } {
@@ -212,7 +213,7 @@ impl Stream for OutgoingBody {
         let sh = match self {
             Self::Empty => return (0, Some(0)),
             Self::Full(full) => full.size_hint(),
-            Self::Boxed(body) => body.size_hint(),
+            Self::Boxed(wrapper) => wrapper.get_ref().size_hint(),
         };
         (
             usize::try_from(sh.lower()).unwrap_or(usize::MAX),
@@ -233,8 +234,8 @@ impl<D> From<Full<D>> for OutgoingBody<D> {
     }
 }
 
-impl<D> From<BoxBody<D, Error>> for OutgoingBody<D> {
-    fn from(value: BoxBody<D, Error>) -> Self {
-        Self::Boxed(value)
+impl<D> From<UnsyncBoxBody<D, Error>> for OutgoingBody<D> {
+    fn from(value: UnsyncBoxBody<D, Error>) -> Self {
+        Self::Boxed(SyncWrapper::new(value))
     }
 }
diff --git a/viz-core/src/middleware/compression.rs b/viz-core/src/middleware/compression.rs
index f41a0e46..e79c952e 100644
--- a/viz-core/src/middleware/compression.rs
+++ b/viz-core/src/middleware/compression.rs
@@ -80,15 +80,11 @@ impl<T: IntoResponse> IntoResponse for Compress<T> {
                 res = res.map(|body| {
                     let body = StreamReader::new(body);
                     if self.algo == ContentCoding::Gzip {
-                        OutgoingBody::streaming(ReaderStream::new(bufread::GzipEncoder::new(body)))
+                        OutgoingBody::stream(ReaderStream::new(bufread::GzipEncoder::new(body)))
                     } else if self.algo == ContentCoding::Deflate {
-                        OutgoingBody::streaming(ReaderStream::new(bufread::DeflateEncoder::new(
-                            body,
-                        )))
+                        OutgoingBody::stream(ReaderStream::new(bufread::DeflateEncoder::new(body)))
                     } else {
-                        OutgoingBody::streaming(ReaderStream::new(bufread::BrotliEncoder::new(
-                            body,
-                        )))
+                        OutgoingBody::stream(ReaderStream::new(bufread::BrotliEncoder::new(body)))
                     }
                 });
                 res.headers_mut()
diff --git a/viz-core/src/response.rs b/viz-core/src/response.rs
index 0701c6c8..2993ad86 100644
--- a/viz-core/src/response.rs
+++ b/viz-core/src/response.rs
@@ -23,6 +23,12 @@ pub trait ResponseExt: private::Sealed + Sized {
     /// [mdn]: <https://developer.mozilla.org/en-US/docs/Web/API/Response/ok>
     fn ok(&self) -> bool;
 
+    /// Creates a response with an empty body.
+    #[must_use]
+    fn empty() -> Response {
+        Response::new(OutgoingBody::default())
+    }
+
     /// The response with the specified [`Content-Type`][mdn].
     ///
     /// [mdn]: <https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type>
@@ -81,11 +87,11 @@ pub trait ResponseExt: private::Sealed + Sized {
     /// Responds to a stream.
     fn stream<S, D, E>(stream: S) -> Response
     where
-        S: Stream<Item = Result<D, E>> + Send + Sync + 'static,
+        S: Stream<Item = Result<D, E>> + Send + 'static,
         D: Into<Bytes> + 'static,
         E: Into<Error> + 'static,
     {
-        Response::new(OutgoingBody::streaming(stream))
+        Response::new(OutgoingBody::stream(stream))
     }
 
     /// Downloads transfers the file from path as an attachment.
@@ -223,7 +229,7 @@ impl ResponseExt for Response {
         .escape_default();
 
         let mut resp = Self::attachment(&format!("attachment; filename=\"{value}\""));
-        *resp.body_mut() = OutgoingBody::streaming(tokio_util::io::ReaderStream::new(
+        *resp.body_mut() = OutgoingBody::stream(tokio_util::io::ReaderStream::new(
             tokio::fs::File::open(path).await.map_err(Error::from)?,
         ));
         Ok(resp)
diff --git a/viz-core/src/types/sse.rs b/viz-core/src/types/sse.rs
index 5a2a2f37..29a1672e 100644
--- a/viz-core/src/types/sse.rs
+++ b/viz-core/src/types/sse.rs
@@ -25,7 +25,7 @@ pub struct Sse<S> {
 
 impl<S> Sse<S>
 where
-    S: Stream<Item = Event> + Send + Sync + 'static,
+    S: Stream<Item = Event> + Send + 'static,
 {
     /// Creates a new Server-Sent Event.
     #[must_use]
@@ -46,7 +46,7 @@ where
 
 impl<S> IntoResponse for Sse<S>
 where
-    S: Stream<Item = Event> + Send + Sync + 'static,
+    S: Stream<Item = Event> + Send + 'static,
 {
     fn into_response(self) -> Response {
         let stream = self.stream.map(|e| Ok::<Bytes, std::io::Error>(e.into()));
diff --git a/viz-router/src/route.rs b/viz-router/src/route.rs
index de380b5d..c86334d7 100644
--- a/viz-router/src/route.rs
+++ b/viz-router/src/route.rs
@@ -167,7 +167,7 @@ impl FromIterator<(Method, BoxHandler)> for Route {
 pub fn on<H, O>(method: Method, handler: H) -> Route
 where
     H: Handler<Request, Output = Result<O>> + Clone,
-    O: IntoResponse + Send + Sync + 'static,
+    O: IntoResponse + Send + 'static,
 {
     Route::new().on(method, handler)
 }