diff --git a/actix-http/CHANGES.md b/actix-http/CHANGES.md
index fc1eea56..26a670e9 100644
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@@ -1,11 +1,13 @@
 # Changes
 
-## [1.0.0-alpha.5] - 2019-12-xx
+## [1.0.0-alpha.5] - 2019-12-09
 
 ### Fixed
 
 * Check `Upgrade` service readiness before calling it
 
+* Fix buffer remaining capacity calcualtion
+
 ### Changed
 
 * Websockets: Ping and Pong should have binary data #1049
diff --git a/actix-http/Cargo.toml b/actix-http/Cargo.toml
index f42604be..c3b228e7 100644
--- a/actix-http/Cargo.toml
+++ b/actix-http/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "actix-http"
-version = "1.0.0-alpha.4"
+version = "1.0.0-alpha.5"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "Actix http primitives"
 readme = "README.md"
diff --git a/actix-http/src/h1/dispatcher.rs b/actix-http/src/h1/dispatcher.rs
index 3bcf1137..1147465b 100644
--- a/actix-http/src/h1/dispatcher.rs
+++ b/actix-http/src/h1/dispatcher.rs
@@ -8,7 +8,7 @@ use actix_codec::{AsyncRead, AsyncWrite, Decoder, Encoder, Framed, FramedParts};
 use actix_rt::time::{delay_until, Delay, Instant};
 use actix_service::Service;
 use bitflags::bitflags;
-use bytes::{BufMut, BytesMut};
+use bytes::BytesMut;
 use log::{error, trace};
 
 use crate::body::{Body, BodySize, MessageBody, ResponseBody};
@@ -751,8 +751,10 @@ where
                     };
 
                     loop {
-                        if inner.write_buf.remaining_mut() < LW_BUFFER_SIZE {
-                            inner.write_buf.reserve(HW_BUFFER_SIZE);
+                        let remaining =
+                            inner.write_buf.capacity() - inner.write_buf.len();
+                        if remaining < LW_BUFFER_SIZE {
+                            inner.write_buf.reserve(HW_BUFFER_SIZE - remaining);
                         }
                         let result = inner.poll_response(cx)?;
                         let drain = result == PollResponse::DrainWriteBuf;
@@ -863,8 +865,9 @@ where
 {
     let mut read_some = false;
     loop {
-        if buf.remaining_mut() < LW_BUFFER_SIZE {
-            buf.reserve(HW_BUFFER_SIZE);
+        let remaining = buf.capacity() - buf.len();
+        if remaining < LW_BUFFER_SIZE {
+            buf.reserve(HW_BUFFER_SIZE - remaining);
         }
 
         match read(cx, io, buf) {