diff --git a/.travis.yml b/.travis.yml
index 640aa1b92..76e1a8c5d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -59,6 +59,7 @@ script:
       cd examples/multipart && cargo check && cd ../..
       cd examples/json && cargo check && cd ../..
       cd examples/juniper && cargo check && cd ../..
+      cd examples/protobuf && cargo check && cd ../..
       cd examples/state && cargo check && cd ../..
       cd examples/template_tera && cargo check && cd ../..
       cd examples/diesel && cargo check && cd ../..
@@ -77,7 +78,7 @@ script:
 after_success:
   - |
     if [[ "$TRAVIS_OS_NAME" == "linux" && "$TRAVIS_PULL_REQUEST" = "false" && "$TRAVIS_BRANCH" == "master" && "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
-      cargo doc --features "alpn, tls" --no-deps &&
+      cargo doc --features "alpn, tls, protobuf" --no-deps &&
       echo "<meta http-equiv=refresh content=0;url=os_balloon/index.html>" > target/doc/index.html &&
       cargo install mdbook &&
       cd guide && mdbook build -d ../target/doc/guide && cd .. &&
diff --git a/CHANGES.md b/CHANGES.md
index 6a08119ff..8ea018081 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,8 +2,12 @@
 
 ## 0.4.6 (2018-03-xx)
 
+* Add experimental protobuf support
+
 * Fix client cookie handling
 
+* Optimize websockets stream support
+
 
 ## 0.4.5 (2018-03-07)
 
diff --git a/Cargo.toml b/Cargo.toml
index dd22754d7..59dd89f7a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,6 +38,9 @@ alpn = ["openssl", "openssl/v102", "openssl/v110", "tokio-openssl"]
 # sessions
 session = ["cookie/secure"]
 
+# protobuf
+protobuf = ["prost"]
+
 [dependencies]
 actix = "^0.5.2"
 
@@ -60,7 +63,6 @@ rand = "0.4"
 regex = "0.2"
 serde = "1.0"
 serde_json = "1.0"
-prost = "^0.2"
 sha1 = "0.6"
 smallvec = "0.6"
 time = "0.1"
@@ -88,6 +90,9 @@ tokio-tls = { version="0.1", optional = true }
 openssl = { version="0.10", optional = true }
 tokio-openssl = { version="0.2", optional = true }
 
+# protobuf
+prost = { version="^0.2", optional = true }
+
 [dev-dependencies]
 env_logger = "0.5"
 skeptic = "0.13"
diff --git a/examples/protobuf/Cargo.toml b/examples/protobuf/Cargo.toml
index 75776ce5a..e5035ec0a 100644
--- a/examples/protobuf/Cargo.toml
+++ b/examples/protobuf/Cargo.toml
@@ -12,4 +12,4 @@ prost = "0.2.0"
 prost-derive = "0.2.0"
 
 actix = "0.5"
-actix-web = { path="../../" }
\ No newline at end of file
+actix-web = { path="../../", features=["protobuf"] }
diff --git a/examples/protobuf/src/main.rs b/examples/protobuf/src/main.rs
index ff411fff8..a7fd2cbee 100644
--- a/examples/protobuf/src/main.rs
+++ b/examples/protobuf/src/main.rs
@@ -8,6 +8,7 @@ extern crate prost;
 extern crate prost_derive;
 
 use actix_web::*;
+use actix_web::ProtoBufBody;
 use futures::Future;
 
 
@@ -22,7 +23,7 @@ pub struct MyObj {
 
 /// This handler uses `HttpRequest::json()` for loading serde json object.
 fn index(req: HttpRequest) -> Box<Future<Item=HttpResponse, Error=Error>> {
-    req.protobuf()
+    ProtoBufBody::new(req)
         .from_err()  // convert all errors into `Error`
         .and_then(|val: MyObj| {
             println!("model: {:?}", val);
diff --git a/src/error.rs b/src/error.rs
index 3c3a088b7..40ecf7045 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -15,8 +15,6 @@ use http::{header, StatusCode, Error as HttpError};
 use http::uri::InvalidUriBytes;
 use http_range::HttpRangeParseError;
 use serde_json::error::Error as JsonError;
-use prost::EncodeError as ProtoBufEncodeError;
-use prost::DecodeError as ProtoBufDecodeError;
 pub use url::ParseError as UrlParseError;
 
 // re-exports
@@ -109,10 +107,6 @@ impl From<failure::Error> for Error {
 /// `InternalServerError` for `JsonError`
 impl ResponseError for JsonError {}
 
-/// `InternalServerError` for `ProtoBufEncodeError` `ProtoBufDecodeError`
-impl ResponseError for ProtoBufEncodeError {}
-impl ResponseError for ProtoBufDecodeError {}
-
 /// `InternalServerError` for `UrlParseError`
 impl ResponseError for UrlParseError {}
 
@@ -456,44 +450,6 @@ impl From<JsonError> for JsonPayloadError {
     }
 }
 
-#[derive(Fail, Debug)]
-pub enum ProtoBufPayloadError {
-    /// Payload size is bigger than 256k
-    #[fail(display="Payload size is bigger than 256k")]
-    Overflow,
-    /// Content type error
-    #[fail(display="Content type error")]
-    ContentType,
-    /// Deserialize error
-    #[fail(display="Json deserialize error: {}", _0)]
-    Deserialize(#[cause] ProtoBufDecodeError),
-    /// Payload error
-    #[fail(display="Error that occur during reading payload: {}", _0)]
-    Payload(#[cause] PayloadError),
-}
-
-impl ResponseError for ProtoBufPayloadError {
-
-    fn error_response(&self) -> HttpResponse {
-        match *self {
-            ProtoBufPayloadError::Overflow => httpcodes::HttpPayloadTooLarge.into(),
-            _ => httpcodes::HttpBadRequest.into(),
-        }
-    }
-}
-
-impl From<PayloadError> for ProtoBufPayloadError {
-    fn from(err: PayloadError) -> ProtoBufPayloadError {
-        ProtoBufPayloadError::Payload(err)
-    }
-}
-
-impl From<ProtoBufDecodeError> for ProtoBufPayloadError {
-    fn from(err: ProtoBufDecodeError) -> ProtoBufPayloadError {
-        ProtoBufPayloadError::Deserialize(err)
-    }
-}
-
 /// Errors which can occur when attempting to interpret a segment string as a
 /// valid path segment.
 #[derive(Fail, Debug, PartialEq)]
diff --git a/src/httpmessage.rs b/src/httpmessage.rs
index 61ab3c4da..69065c49c 100644
--- a/src/httpmessage.rs
+++ b/src/httpmessage.rs
@@ -4,7 +4,6 @@ use bytes::{Bytes, BytesMut};
 use futures::{Future, Stream, Poll};
 use http_range::HttpRange;
 use serde::de::DeserializeOwned;
-use prost::Message;
 use mime::Mime;
 use url::form_urlencoded;
 use encoding::all::UTF_8;
@@ -13,7 +12,6 @@ use encoding::label::encoding_from_whatwg_label;
 use http::{header, HeaderMap};
 
 use json::JsonBody;
-use protobuf::ProtoBufBody;
 use header::Header;
 use multipart::Multipart;
 use error::{ParseError, ContentTypeError,
@@ -211,12 +209,6 @@ pub trait HttpMessage {
         JsonBody::new(self)
     }
 
-    fn protobuf<T: Message + Default>(self) -> ProtoBufBody<Self, T>
-        where Self: Stream<Item=Bytes, Error=PayloadError> + Sized
-    {
-        ProtoBufBody::new(self)
-    }
-
     /// Return stream to http payload processes as multipart.
     ///
     /// Content-type: multipart/form-data;
diff --git a/src/httpresponse.rs b/src/httpresponse.rs
index 2147a42c1..9c99d4d68 100644
--- a/src/httpresponse.rs
+++ b/src/httpresponse.rs
@@ -11,7 +11,6 @@ use http::{StatusCode, Version, HeaderMap, HttpTryFrom, Error as HttpError};
 use http::header::{self, HeaderName, HeaderValue};
 use serde_json;
 use serde::Serialize;
-use prost::Message;
 
 use body::Body;
 use error::Error;
@@ -509,22 +508,6 @@ impl HttpResponseBuilder {
         Ok(self.body(body)?)
     }
 
-    pub fn protobuf<T: Message>(&mut self, value: T) -> Result<HttpResponse, Error> {
-        let mut body = Vec::new();
-        value.encode(&mut body)?;
-        
-        let contains = if let Some(parts) = parts(&mut self.response, &self.err) {
-            parts.headers.contains_key(header::CONTENT_TYPE)
-        } else {
-            true
-        };
-        if !contains {
-            self.header(header::CONTENT_TYPE, "application/protobuf");
-        }
-
-        Ok(self.body(body)?)
-    }
-
     /// Set an empty body and generate `HttpResponse`
     ///
     /// `HttpResponseBuilder` can not be used after this call.
diff --git a/src/lib.rs b/src/lib.rs
index 39e1e48a9..8c021ca99 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -78,7 +78,6 @@ extern crate url;
 extern crate libc;
 extern crate serde;
 extern crate serde_json;
-extern crate prost;
 extern crate flate2;
 extern crate brotli2;
 extern crate encoding;
@@ -89,6 +88,9 @@ extern crate h2 as http2;
 extern crate trust_dns_resolver;
 #[macro_use] extern crate actix;
 
+#[cfg(feature="protobuf")]
+extern crate prost;
+
 #[cfg(test)]
 #[macro_use] extern crate serde_derive;
 
@@ -112,7 +114,6 @@ mod httprequest;
 mod httpresponse;
 mod info;
 mod json;
-mod protobuf;
 mod route;
 mod router;
 mod resource;
@@ -120,6 +121,11 @@ mod param;
 mod payload;
 mod pipeline;
 
+#[cfg(feature="protobuf")]
+mod protobuf;
+#[cfg(feature="protobuf")]
+pub use protobuf::{ProtoBuf, ProtoBufBody};
+
 pub mod client;
 pub mod fs;
 pub mod ws;
@@ -134,7 +140,6 @@ pub mod server;
 pub use error::{Error, Result, ResponseError};
 pub use body::{Body, Binary};
 pub use json::Json;
-pub use protobuf::ProtoBuf;
 pub use application::Application;
 pub use httpmessage::HttpMessage;
 pub use httprequest::HttpRequest;
diff --git a/src/protobuf.rs b/src/protobuf.rs
index 439f26179..e0147a1de 100644
--- a/src/protobuf.rs
+++ b/src/protobuf.rs
@@ -1,16 +1,60 @@
 use bytes::{Bytes, BytesMut};
 use futures::{Poll, Future, Stream};
-use http::header::CONTENT_LENGTH;
+use http::header::{CONTENT_TYPE, CONTENT_LENGTH};
 
 use bytes::IntoBuf;
 use prost::Message;
+use prost::EncodeError as ProtoBufEncodeError;
+use prost::DecodeError as ProtoBufDecodeError;
 
-use error::{Error, ProtoBufPayloadError, PayloadError};
+use error::{Error, PayloadError, ResponseError};
 use handler::Responder;
 use httpmessage::HttpMessage;
 use httprequest::HttpRequest;
-use httpresponse::HttpResponse;
+use httpresponse::{HttpResponse, HttpResponseBuilder};
+use httpcodes::{HttpBadRequest, HttpPayloadTooLarge};
 
+#[derive(Fail, Debug)]
+pub enum ProtoBufPayloadError {
+    /// Payload size is bigger than 256k
+    #[fail(display="Payload size is bigger than 256k")]
+    Overflow,
+    /// Content type error
+    #[fail(display="Content type error")]
+    ContentType,
+    /// Deserialize error
+    #[fail(display="Json deserialize error: {}", _0)]
+    Deserialize(#[cause] ProtoBufDecodeError),
+    /// Payload error
+    #[fail(display="Error that occur during reading payload: {}", _0)]
+    Payload(#[cause] PayloadError),
+}
+
+impl ResponseError for ProtoBufPayloadError {
+
+    fn error_response(&self) -> HttpResponse {
+        match *self {
+            ProtoBufPayloadError::Overflow => HttpPayloadTooLarge.into(),
+            _ => HttpBadRequest.into(),
+        }
+    }
+}
+
+impl From<PayloadError> for ProtoBufPayloadError {
+    fn from(err: PayloadError) -> ProtoBufPayloadError {
+        ProtoBufPayloadError::Payload(err)
+    }
+}
+
+impl From<ProtoBufDecodeError> for ProtoBufPayloadError {
+    fn from(err: ProtoBufDecodeError) -> ProtoBufPayloadError {
+        ProtoBufPayloadError::Deserialize(err)
+    }
+}
+
+/// `InternalServerError` for `ProtoBufEncodeError` `ProtoBufDecodeError`
+impl ResponseError for ProtoBufEncodeError {}
+impl ResponseError for ProtoBufDecodeError {}
 
 #[derive(Debug)]
 pub struct ProtoBuf<T: Message>(pub T);
@@ -32,9 +76,6 @@ impl<T: Message> Responder for ProtoBuf<T> {
     }
 }
 
-
-
-
 pub struct ProtoBufBody<T, U: Message + Default>{
     limit: usize,
     ct: &'static str,
@@ -110,4 +151,16 @@ impl<T, U: Message + Default + 'static> Future for ProtoBufBody<T, U>
 
         self.fut.as_mut().expect("ProtoBufBody could not be used second time").poll()
     }
-}
\ No newline at end of file
+}
+
+
+impl HttpResponseBuilder {
+
+    pub fn protobuf<T: Message>(&mut self, value: T) -> Result<HttpResponse, Error> {
+        self.header(CONTENT_TYPE, "application/protobuf");
+
+        let mut body = Vec::new();
+        value.encode(&mut body)?;
+        Ok(self.body(body)?)
+    }
+}