diff --git a/src/lib.rs b/src/lib.rs
index 4e6e37955..8750b24ca 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -89,12 +89,11 @@ pub mod h2;
 pub mod test;
 pub mod ws;
 
-pub use self::body::{Body, MessageBody};
 pub use self::config::{KeepAlive, ServiceConfig, ServiceConfigBuilder};
 pub use self::error::{Error, ResponseError, Result};
 pub use self::extensions::Extensions;
 pub use self::httpmessage::HttpMessage;
-pub use self::message::{Message, RequestHead, ResponseHead};
+pub use self::message::{Head, Message, RequestHead, ResponseHead};
 pub use self::payload::{Payload, PayloadStream};
 pub use self::request::Request;
 pub use self::response::Response;
diff --git a/src/response.rs b/src/response.rs
index d84100fa2..0295758b2 100644
--- a/src/response.rs
+++ b/src/response.rs
@@ -242,6 +242,20 @@ impl<B: MessageBody> Response<B> {
             self.body,
         )
     }
+
+    /// Set a body and return previous body value
+    pub fn map_body<F, B2: MessageBody>(mut self, f: F) -> Response<B2>
+    where
+        F: FnOnce(&mut ResponseHead, ResponseBody<B>) -> ResponseBody<B2>,
+    {
+        let body = f(&mut self.head, self.body);
+
+        Response {
+            head: self.head,
+            body: body,
+            error: self.error,
+        }
+    }
 }
 
 impl<B: MessageBody> fmt::Debug for Response<B> {