diff --git a/Cargo.toml b/Cargo.toml
index 563642105..e6c241f8b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -76,7 +76,7 @@ lazy_static = "1.0"
 url = { version="1.7", features=["query_encoding"] }
 cookie = { version="0.10", features=["percent-encode"] }
 brotli2 = { version="^0.3.2", optional = true }
-flate2 = { version="1.0", default-features = false }
+flate2 = { version="1.0", optional = true, default-features = false }
 
 # io
 mio = "^0.6.13"
diff --git a/src/client/writer.rs b/src/client/writer.rs
index 48e4cc711..36c9d6ee0 100644
--- a/src/client/writer.rs
+++ b/src/client/writer.rs
@@ -7,8 +7,10 @@ use std::io::{self, Write};
 #[cfg(feature = "brotli")]
 use brotli2::write::BrotliEncoder;
 use bytes::{BufMut, BytesMut};
-use flate2::Compression;
+#[cfg(feature = "flate2")]
 use flate2::write::{DeflateEncoder, GzEncoder};
+#[cfg(feature = "flate2")]
+use flate2::Compression;
 use futures::{Async, Poll};
 use http::header::{HeaderValue, CONNECTION, CONTENT_ENCODING, CONTENT_LENGTH, DATE,
                    TRANSFER_ENCODING};
@@ -18,9 +20,9 @@ use tokio_io::AsyncWrite;
 
 use body::{Binary, Body};
 use header::ContentEncoding;
-use server::WriterState;
 use server::encoding::{ContentEncoder, TransferEncoding};
 use server::shared::SharedBytes;
+use server::WriterState;
 
 use client::ClientRequest;
 
@@ -70,7 +72,7 @@ impl HttpClientWriter {
     // !self.flags.contains(Flags::UPGRADE) }
 
     fn write_to_stream<T: AsyncWrite>(
-        &mut self, stream: &mut T
+        &mut self, stream: &mut T,
     ) -> io::Result<WriterState> {
         while !self.buffer.is_empty() {
             match stream.write(self.buffer.as_ref()) {
@@ -191,7 +193,7 @@ impl HttpClientWriter {
 
     #[inline]
     pub fn poll_completed<T: AsyncWrite>(
-        &mut self, stream: &mut T, shutdown: bool
+        &mut self, stream: &mut T, shutdown: bool,
     ) -> Poll<(), io::Error> {
         match self.write_to_stream(stream) {
             Ok(WriterState::Done) => {
@@ -222,9 +224,11 @@ fn content_encoder(buf: SharedBytes, req: &mut ClientRequest) -> ContentEncoder
                 let tmp = SharedBytes::default();
                 let transfer = TransferEncoding::eof(tmp.clone());
                 let mut enc = match encoding {
+                    #[cfg(feature = "flate2")]
                     ContentEncoding::Deflate => ContentEncoder::Deflate(
                         DeflateEncoder::new(transfer, Compression::default()),
                     ),
+                    #[cfg(feature = "flate2")]
                     ContentEncoding::Gzip => ContentEncoder::Gzip(GzEncoder::new(
                         transfer,
                         Compression::default(),
@@ -283,10 +287,12 @@ fn content_encoder(buf: SharedBytes, req: &mut ClientRequest) -> ContentEncoder
 
     req.replace_body(body);
     match encoding {
+        #[cfg(feature = "flate2")]
         ContentEncoding::Deflate => ContentEncoder::Deflate(DeflateEncoder::new(
             transfer,
             Compression::default(),
         )),
+        #[cfg(feature = "flate2")]
         ContentEncoding::Gzip => {
             ContentEncoder::Gzip(GzEncoder::new(transfer, Compression::default()))
         }
@@ -299,7 +305,7 @@ fn content_encoder(buf: SharedBytes, req: &mut ClientRequest) -> ContentEncoder
 }
 
 fn streaming_encoding(
-    buf: SharedBytes, version: Version, req: &mut ClientRequest
+    buf: SharedBytes, version: Version, req: &mut ClientRequest,
 ) -> TransferEncoding {
     if req.chunked() {
         // Enable transfer encoding
diff --git a/src/header/mod.rs b/src/header/mod.rs
index 3564da9e2..7d791c7b8 100644
--- a/src/header/mod.rs
+++ b/src/header/mod.rs
@@ -6,8 +6,8 @@ use std::str::FromStr;
 
 use bytes::{Bytes, BytesMut};
 use mime::Mime;
-use modhttp::Error as HttpError;
 use modhttp::header::GetAll;
+use modhttp::Error as HttpError;
 
 pub use modhttp::header::*;
 
@@ -116,8 +116,10 @@ pub enum ContentEncoding {
     #[cfg(feature = "brotli")]
     Br,
     /// A format using the zlib structure with deflate algorithm
+    #[cfg(feature = "flate2")]
     Deflate,
     /// Gzip algorithm
+    #[cfg(feature = "flate2")]
     Gzip,
     /// Indicates the identity function (i.e. no compression, nor modification)
     Identity,
@@ -137,7 +139,9 @@ impl ContentEncoding {
         match *self {
             #[cfg(feature = "brotli")]
             ContentEncoding::Br => "br",
+            #[cfg(feature = "flate2")]
             ContentEncoding::Gzip => "gzip",
+            #[cfg(feature = "flate2")]
             ContentEncoding::Deflate => "deflate",
             ContentEncoding::Identity | ContentEncoding::Auto => "identity",
         }
@@ -149,7 +153,9 @@ impl ContentEncoding {
         match *self {
             #[cfg(feature = "brotli")]
             ContentEncoding::Br => 1.1,
+            #[cfg(feature = "flate2")]
             ContentEncoding::Gzip => 1.0,
+            #[cfg(feature = "flate2")]
             ContentEncoding::Deflate => 0.9,
             ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
         }
@@ -159,10 +165,12 @@ impl ContentEncoding {
 // TODO: remove memory allocation
 impl<'a> From<&'a str> for ContentEncoding {
     fn from(s: &'a str) -> ContentEncoding {
-        match s.trim().to_lowercase().as_ref() {
+        match AsRef::<str>::as_ref(&s.trim().to_lowercase()) {
             #[cfg(feature = "brotli")]
             "br" => ContentEncoding::Br,
+            #[cfg(feature = "flate2")]
             "gzip" => ContentEncoding::Gzip,
+            #[cfg(feature = "flate2")]
             "deflate" => ContentEncoding::Deflate,
             _ => ContentEncoding::Identity,
         }
@@ -202,7 +210,7 @@ impl fmt::Write for Writer {
 #[doc(hidden)]
 /// Reads a comma-delimited raw header into a Vec.
 pub fn from_comma_delimited<T: FromStr>(
-    all: GetAll<HeaderValue>
+    all: GetAll<HeaderValue>,
 ) -> Result<Vec<T>, ParseError> {
     let mut result = Vec::new();
     for h in all {
diff --git a/src/lib.rs b/src/lib.rs
index 1a0ac8ade..2efac129e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -64,8 +64,10 @@
 #![cfg_attr(actix_nightly, feature(
     specialization, // for impl ErrorResponse for std::error::Error
 ))]
-#![cfg_attr(feature = "cargo-clippy",
-            allow(decimal_literal_representation, suspicious_arithmetic_impl))]
+#![cfg_attr(
+    feature = "cargo-clippy",
+    allow(decimal_literal_representation, suspicious_arithmetic_impl)
+)]
 
 #[macro_use]
 extern crate log;
@@ -103,6 +105,7 @@ extern crate serde;
 #[cfg(feature = "brotli")]
 extern crate brotli2;
 extern crate encoding;
+#[cfg(feature = "flate2")]
 extern crate flate2;
 extern crate h2 as http2;
 extern crate num_cpus;
diff --git a/src/server/encoding.rs b/src/server/encoding.rs
index 7c886fe5c..ae69ae07f 100644
--- a/src/server/encoding.rs
+++ b/src/server/encoding.rs
@@ -6,11 +6,14 @@ use std::{cmp, io, mem};
 #[cfg(feature = "brotli")]
 use brotli2::write::{BrotliDecoder, BrotliEncoder};
 use bytes::{BufMut, Bytes, BytesMut};
-use flate2::Compression;
+#[cfg(feature = "flate2")]
 use flate2::read::GzDecoder;
+#[cfg(feature = "flate2")]
 use flate2::write::{DeflateDecoder, DeflateEncoder, GzEncoder};
-use http::header::{HeaderMap, HeaderValue, ACCEPT_ENCODING,
-                   CONTENT_ENCODING, CONTENT_LENGTH, TRANSFER_ENCODING};
+#[cfg(feature = "flate2")]
+use flate2::Compression;
+use http::header::{HeaderMap, HeaderValue, ACCEPT_ENCODING, CONTENT_ENCODING,
+                   CONTENT_LENGTH, TRANSFER_ENCODING};
 use http::{HttpTryFrom, Method, Version};
 
 use body::{Binary, Body};
@@ -144,7 +147,9 @@ impl PayloadWriter for EncodedPayload {
 }
 
 pub(crate) enum Decoder {
+    #[cfg(feature = "flate2")]
     Deflate(Box<DeflateDecoder<Writer>>),
+    #[cfg(feature = "flate2")]
     Gzip(Option<Box<GzDecoder<Wrapper>>>),
     #[cfg(feature = "brotli")]
     Br(Box<BrotliDecoder<Writer>>),
@@ -223,9 +228,11 @@ impl PayloadStream {
             ContentEncoding::Br => {
                 Decoder::Br(Box::new(BrotliDecoder::new(Writer::new())))
             }
+            #[cfg(feature = "flate2")]
             ContentEncoding::Deflate => {
                 Decoder::Deflate(Box::new(DeflateDecoder::new(Writer::new())))
             }
+            #[cfg(feature = "flate2")]
             ContentEncoding::Gzip => Decoder::Gzip(None),
             _ => Decoder::Identity,
         };
@@ -251,6 +258,7 @@ impl PayloadStream {
                 }
                 Err(e) => Err(e),
             },
+            #[cfg(feature = "flate2")]
             Decoder::Gzip(ref mut decoder) => {
                 if let Some(ref mut decoder) = *decoder {
                     decoder.as_mut().get_mut().eof = true;
@@ -267,6 +275,7 @@ impl PayloadStream {
                     Ok(None)
                 }
             }
+            #[cfg(feature = "flate2")]
             Decoder::Deflate(ref mut decoder) => match decoder.try_finish() {
                 Ok(_) => {
                     let b = decoder.get_mut().take();
@@ -297,6 +306,7 @@ impl PayloadStream {
                 }
                 Err(e) => Err(e),
             },
+            #[cfg(feature = "flate2")]
             Decoder::Gzip(ref mut decoder) => {
                 if decoder.is_none() {
                     *decoder = Some(Box::new(GzDecoder::new(Wrapper {
@@ -334,6 +344,7 @@ impl PayloadStream {
                     }
                 }
             }
+            #[cfg(feature = "flate2")]
             Decoder::Deflate(ref mut decoder) => match decoder.write_all(&data) {
                 Ok(_) => {
                     decoder.flush()?;
@@ -352,7 +363,9 @@ impl PayloadStream {
 }
 
 pub(crate) enum ContentEncoder {
+    #[cfg(feature = "flate2")]
     Deflate(DeflateEncoder<TransferEncoding>),
+    #[cfg(feature = "flate2")]
     Gzip(GzEncoder<TransferEncoding>),
     #[cfg(feature = "brotli")]
     Br(BrotliEncoder<TransferEncoding>),
@@ -422,9 +435,11 @@ impl ContentEncoder {
                     let tmp = SharedBytes::default();
                     let transfer = TransferEncoding::eof(tmp.clone());
                     let mut enc = match encoding {
+                        #[cfg(feature = "flate2")]
                         ContentEncoding::Deflate => ContentEncoder::Deflate(
                             DeflateEncoder::new(transfer, Compression::fast()),
                         ),
+                        #[cfg(feature = "flate2")]
                         ContentEncoding::Gzip => ContentEncoder::Gzip(GzEncoder::new(
                             transfer,
                             Compression::fast(),
@@ -478,10 +493,12 @@ impl ContentEncoder {
         }
 
         match encoding {
+            #[cfg(feature = "flate2")]
             ContentEncoding::Deflate => ContentEncoder::Deflate(DeflateEncoder::new(
                 transfer,
                 Compression::fast(),
             )),
+            #[cfg(feature = "flate2")]
             ContentEncoding::Gzip => {
                 ContentEncoder::Gzip(GzEncoder::new(transfer, Compression::fast()))
             }
@@ -494,7 +511,7 @@ impl ContentEncoder {
     }
 
     fn streaming_encoding(
-        buf: SharedBytes, version: Version, resp: &mut HttpResponse
+        buf: SharedBytes, version: Version, resp: &mut HttpResponse,
     ) -> TransferEncoding {
         match resp.chunked() {
             Some(true) => {
@@ -563,7 +580,9 @@ impl ContentEncoder {
         match *self {
             #[cfg(feature = "brotli")]
             ContentEncoder::Br(ref encoder) => encoder.get_ref().is_eof(),
+            #[cfg(feature = "flate2")]
             ContentEncoder::Deflate(ref encoder) => encoder.get_ref().is_eof(),
+            #[cfg(feature = "flate2")]
             ContentEncoder::Gzip(ref encoder) => encoder.get_ref().is_eof(),
             ContentEncoder::Identity(ref encoder) => encoder.is_eof(),
         }
@@ -587,6 +606,7 @@ impl ContentEncoder {
                 }
                 Err(err) => Err(err),
             },
+            #[cfg(feature = "flate2")]
             ContentEncoder::Gzip(encoder) => match encoder.finish() {
                 Ok(mut writer) => {
                     writer.encode_eof();
@@ -595,6 +615,7 @@ impl ContentEncoder {
                 }
                 Err(err) => Err(err),
             },
+            #[cfg(feature = "flate2")]
             ContentEncoder::Deflate(encoder) => match encoder.finish() {
                 Ok(mut writer) => {
                     writer.encode_eof();
@@ -625,6 +646,7 @@ impl ContentEncoder {
                     }
                 }
             }
+            #[cfg(feature = "flate2")]
             ContentEncoder::Gzip(ref mut encoder) => {
                 match encoder.write_all(data.as_ref()) {
                     Ok(_) => Ok(()),
@@ -634,6 +656,7 @@ impl ContentEncoder {
                     }
                 }
             }
+            #[cfg(feature = "flate2")]
             ContentEncoder::Deflate(ref mut encoder) => {
                 match encoder.write_all(data.as_ref()) {
                     Ok(_) => Ok(()),