diff --git a/tonic/Cargo.toml b/tonic/Cargo.toml
index 8e0321c..a170d1e 100644
--- a/tonic/Cargo.toml
+++ b/tonic/Cargo.toml
@@ -11,7 +11,7 @@ tracing = "0.1"
 http = "0.1.14"
 base64 = "0.10"
 bytes = "0.4.7"
-prost = "0.5"
+
 percent-encoding = "1.0.1"
 tower-service = "=0.3.0-alpha.1"
 tokio-codec = "=0.2.0-alpha.4"
@@ -19,6 +19,9 @@ async-stream = "0.1.1"
 http-body = "0.2.0-alpha.1"
 pin-project = "=0.4.0-alpha.11"
 
+# prost
+prost = { version = "0.5", optional = true }
+
 # codegen
 async-trait = { version = "0.1.13", optional = true }
 
@@ -39,7 +42,7 @@ openssl1 = { package = "openssl", version = "0.10", optional = true }
 tokio-rustls = { version = "0.12.0-alpha.2", optional = true }
 
 [features]
-default = ["transport", "codegen"]
+default = ["transport", "codegen", "prost"]
 codegen = ["async-trait"]
 transport = [
     "hyper",
diff --git a/tonic/src/client/mod.rs b/tonic/src/client/mod.rs
index 091608e..3534058 100644
--- a/tonic/src/client/mod.rs
+++ b/tonic/src/client/mod.rs
@@ -1,4 +1,4 @@
-//! gRPC client implementation.
+//! Generic client implementation.
 //!
 //! This module contains the low level components to build a gRPC client. It
 //! provides a codec agnostic gRPC client dispatcher and a decorated tower
diff --git a/tonic/src/codec/mod.rs b/tonic/src/codec/mod.rs
index 241afae..b75fea5 100644
--- a/tonic/src/codec/mod.rs
+++ b/tonic/src/codec/mod.rs
@@ -1,20 +1,22 @@
-//! gRPC encoding and decoding.
+//! Generic encoding and decoding.
 //!
 //! This module contains the generic `Codec` trait and a protobuf codec
 //! based on prost.
 
 mod decode;
 mod encode;
+#[cfg(feature = "prost")]
 mod prost;
 
 pub use self::decode::Streaming;
 pub(crate) use self::encode::{encode_client, encode_server};
+#[cfg(feature = "prost")]
 pub use self::prost::ProstCodec;
 pub use tokio_codec::{Decoder, Encoder};
 
 use crate::Status;
 
-/// Triat that knows how to encode and decode gRPC messages.
+/// Trait that knows how to encode and decode gRPC messages.
 pub trait Codec {
     /// The encodable message.
     type Encode: Send + 'static;
diff --git a/tonic/src/lib.rs b/tonic/src/lib.rs
index 639057a..a91b9dd 100644
--- a/tonic/src/lib.rs
+++ b/tonic/src/lib.rs
@@ -30,13 +30,14 @@
 //! enabled by default.
 //! - `rustls`: Enables the `ruslts` based tls options for the `transport` feature`. Not
 //! enabled by default.
+//! - `prost`: Enables the [`prost`] based gRPC [`Codec`] implementation.
 //!
 //! # Structure
 //!
 //! ## Generic implementation
 //!
 //! The main goal of [`tonic`] is to provide a generic gRPC implementation over http2.0
-//! framing. This means at the lowest level this library provides the ability to 
+//! framing. This means at the lowest level this library provides the ability to
 //!
 //! TODO: write generic implementation docs
 //!
diff --git a/tonic/src/metadata/mod.rs b/tonic/src/metadata/mod.rs
index 12c9c53..8389681 100644
--- a/tonic/src/metadata/mod.rs
+++ b/tonic/src/metadata/mod.rs
@@ -1,5 +1,4 @@
-//! The metadata module contains data structures and utilities for handling
-//! gRPC custom metadata.
+//! Contains data structures and utilities for handling gRPC custom metadata.
 
 mod encoding;
 mod key;
diff --git a/tonic/src/server/mod.rs b/tonic/src/server/mod.rs
index 7f6deb5..c1be1c2 100644
--- a/tonic/src/server/mod.rs
+++ b/tonic/src/server/mod.rs
@@ -1,9 +1,9 @@
-//! gRPC server implementation.
+//! Generic server implementation.
 //!
 //! This module contains the low level components to build a gRPC server. It
 //! provides a codec agnostic gRPC server handler.
 //!
-//! The items in this module are generally desgined to be used by some codegen
+//! The items in this module are generally designed to be used by some codegen
 //! tool that will provide the user some custom way to implement the server that
 //! will implement the proper gRPC service. Thusly, they are a bit hard to use
 //! by hand.