diff --git a/examples/simple_site.rs b/examples/simple_site.rs
index faa7af7..da052f5 100755
--- a/examples/simple_site.rs
+++ b/examples/simple_site.rs
@@ -1,5 +1,6 @@
 use std::time::Duration;
 
+use async_trait::async_trait;
 use ezhttp::{
     body::Body, 
     headers::Headers, 
@@ -62,14 +63,15 @@ impl EzSite {
     }
 }
 
+#[async_trait]
 impl HttpServer for EzSite {
-    async fn on_request(&self, req: &HttpRequest) -> Option<impl Sendable> {
+    async fn on_request(&self, req: &HttpRequest) -> Option<Box<dyn Sendable>> {
         println!("{} > {} {}", req.addr, req.method, req.url.to_path_string());
 
         if let Some(resp) = self.get_main_page(req).await {
-            Some(resp)
+            Some(resp.as_box())
         } else if let Some(resp) = self.get_unknown_page(req).await {
-            Some(resp)
+            Some(resp.as_box())
         } else {
             None // shutdown connection
         }
diff --git a/examples/small_site.rs b/examples/small_site.rs
index e9b2793..cb53108 100755
--- a/examples/small_site.rs
+++ b/examples/small_site.rs
@@ -1,9 +1,11 @@
+use async_trait::async_trait;
 use ezhttp::{prelude::*, Sendable};
 
 struct EzSite(String);
 
+#[async_trait]
 impl HttpServer for EzSite {
-    async fn on_request(&self, req: &HttpRequest) -> Option<impl Sendable> {
+    async fn on_request(&self, req: &HttpRequest) -> Option<Box<dyn Sendable>> {
         println!("{} > {} {}", req.addr, req.method, req.url.to_path_string());
 
         if req.url.path == "/" {
@@ -13,7 +15,7 @@ impl HttpServer for EzSite {
                     ("Content-Type", "text/html"),                                 // - content type
                     ("Content-Length", self.0.len().to_string().as_str())          // - content length
                 ]), Body::from_text(&self.0.clone()),                              // response body
-            ))
+            ).as_box())
         } else {
             None // close connection
         }
diff --git a/src/ezhttp/body.rs b/src/ezhttp/body.rs
index 74ce284..9b11a07 100755
--- a/src/ezhttp/body.rs
+++ b/src/ezhttp/body.rs
@@ -160,6 +160,9 @@ impl Sendable for Body {
     ) -> Result<(), HttpError> {
         stream.write_all(&self.as_bytes()).await.map_err(|_| HttpError::WriteHeadError)
     }
+    fn as_box(self) -> Box<dyn Sendable> {
+        Box::new(self)
+    }
 }
 
 impl Default for Body {
diff --git a/src/ezhttp/headers.rs b/src/ezhttp/headers.rs
index 397b161..531948b 100755
--- a/src/ezhttp/headers.rs
+++ b/src/ezhttp/headers.rs
@@ -144,4 +144,7 @@ impl Sendable for Headers {
         }
         stream.write_all(head.as_bytes()).await.map_err(|_| HttpError::WriteHeadError)
     }
+    fn as_box(self) -> Box<dyn Sendable> {
+        Box::new(self)
+    }
 }
\ No newline at end of file
diff --git a/src/ezhttp/mod.rs b/src/ezhttp/mod.rs
index 2ab4401..a325890 100755
--- a/src/ezhttp/mod.rs
+++ b/src/ezhttp/mod.rs
@@ -16,7 +16,8 @@ pub mod prelude {
     pub use super::server::*;
     pub use super::server::handler::*;
     pub use super::server::starter::*;
-    pub use super::client::*;
+    // pub use super::client::*;
+    pub use super::*;
 }
 
 use error::HttpError;
@@ -113,6 +114,7 @@ pub trait Sendable: Send + Sync {
         &self,
         stream: &mut (dyn AsyncWrite + Unpin + Send + Sync),
     ) -> Result<(), HttpError>;
+    fn as_box(self) -> Box<dyn Sendable>;
 }
 
 pub type Stream = TimeoutStream<TcpStream>;
\ No newline at end of file
diff --git a/src/ezhttp/request.rs b/src/ezhttp/request.rs
index 1047a20..ddd3928 100755
--- a/src/ezhttp/request.rs
+++ b/src/ezhttp/request.rs
@@ -216,4 +216,7 @@ impl Sendable for HttpRequest {
 
         Ok(())
     }
+    fn as_box(self) -> Box<dyn Sendable> {
+        Box::new(self)
+    }
 }
\ No newline at end of file
diff --git a/src/ezhttp/response.rs b/src/ezhttp/response.rs
index 0c35915..8566a64 100755
--- a/src/ezhttp/response.rs
+++ b/src/ezhttp/response.rs
@@ -93,4 +93,7 @@ impl Sendable for HttpResponse {
 
         Ok(())
     }
+    fn as_box(self) -> Box<dyn Sendable> {
+        Box::new(self)
+    }
 }