diff --git a/src/proto/codec.rs b/src/proto/codec.rs
index d1b8b8e..877d527 100644
--- a/src/proto/codec.rs
+++ b/src/proto/codec.rs
@@ -4,10 +4,12 @@
 
 use std::convert::TryInto;
 use std::io;
-use std::marker;
+use std::marker::PhantomData;
 
 use bytes::BytesMut;
 use thiserror::Error;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpStream;
 
 use super::prefix::Prefixer;
 use super::u32::{decode_u32, U32_BYTE_LEN};
@@ -35,14 +37,15 @@ impl From<FrameEncodeError> for io::Error {
 }
 
 /// Encodes entire protocol frames containing values of type `T`.
+#[derive(Debug)]
 pub struct FrameEncoder<T: ?Sized> {
-    phantom: marker::PhantomData<T>,
+    phantom: PhantomData<T>,
 }
 
 impl<T: ValueEncode + ?Sized> FrameEncoder<T> {
     pub fn new() -> Self {
         Self {
-            phantom: marker::PhantomData,
+            phantom: PhantomData,
         }
     }
 
@@ -66,15 +69,16 @@ impl<T: ValueEncode + ?Sized> FrameEncoder<T> {
 }
 
 /// Decodes entire protocol frames containing values of type `T`.
+#[derive(Debug)]
 pub struct FrameDecoder<T> {
     // Only here to enable parameterizing `Decoder` by `T`.
-    phantom: marker::PhantomData<T>,
+    phantom: PhantomData<T>,
 }
 
 impl<T: ValueDecode> FrameDecoder<T> {
     pub fn new() -> Self {
         Self {
-            phantom: marker::PhantomData,
+            phantom: PhantomData,
         }
     }
 
@@ -140,10 +144,51 @@ impl<T: ValueDecode> FrameDecoder<T> {
     }
 }
 
+#[derive(Debug)]
+pub struct Connection<ReadFrame, WriteFrame: ?Sized> {
+    stream: TcpStream,
+
+    read_buffer: BytesMut,
+
+    decoder: FrameDecoder<ReadFrame>,
+    encoder: FrameEncoder<WriteFrame>,
+}
+
+impl<ReadFrame, WriteFrame> Connection<ReadFrame, WriteFrame>
+where
+    ReadFrame: ValueDecode,
+    WriteFrame: ValueEncode + ?Sized,
+{
+    pub fn new(stream: TcpStream) -> Self {
+        Connection {
+            stream,
+            read_buffer: BytesMut::new(),
+            decoder: FrameDecoder::new(),
+            encoder: FrameEncoder::new(),
+        }
+    }
+
+    pub async fn read(&mut self) -> io::Result<ReadFrame> {
+        loop {
+            if let Some(frame) = self.decoder.decode_from(&mut self.read_buffer)? {
+                return Ok(frame);
+            }
+            self.stream.read_buf(&mut self.read_buffer).await?;
+        }
+    }
+
+    pub async fn write(&mut self, frame: &WriteFrame) -> io::Result<()> {
+        let mut bytes = BytesMut::new();
+        self.encoder.encode_to(frame, &mut bytes)?;
+        self.stream.write_all(bytes.as_ref()).await
+    }
+}
+
 mod tests {
     use bytes::BytesMut;
+    use tokio::net::{TcpListener, TcpStream};
 
-    use super::{FrameDecoder, FrameEncoder};
+    use super::{Connection, FrameDecoder, FrameEncoder};
 
     // Test value: [1, 3, 3, 7] in little-endian.
     const U32_1337: u32 = 1 + (3 << 8) + (3 << 16) + (7 << 24);
@@ -289,4 +334,52 @@ mod tests {
         assert_eq!(decoded, Some(value));
         assert_eq!(buffer, vec![]);
     }
+
+    #[tokio::test]
+    async fn ping_pong() {
+        let listener = TcpListener::bind("localhost:0").await.unwrap();
+        let address = listener.local_addr().unwrap();
+
+        let server_task = tokio::spawn(async move {
+            let (stream, _peer_address) = listener.accept().await.unwrap();
+            let mut connection = Connection::<String, str>::new(stream);
+
+            assert_eq!(connection.read().await.unwrap(), "ping");
+            connection.write("pong").await.unwrap();
+            assert_eq!(connection.read().await.unwrap(), "ping");
+            connection.write("pong").await.unwrap();
+        });
+
+        let stream = TcpStream::connect(address).await.unwrap();
+        let mut connection = Connection::<String, str>::new(stream);
+
+        connection.write("ping").await.unwrap();
+        assert_eq!(connection.read().await.unwrap(), "pong");
+        connection.write("ping").await.unwrap();
+        assert_eq!(connection.read().await.unwrap(), "pong");
+
+        server_task.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn very_large_message() {
+        let listener = TcpListener::bind("localhost:0").await.unwrap();
+        let address = listener.local_addr().unwrap();
+
+        let server_task = tokio::spawn(async move {
+            let (stream, _peer_address) = listener.accept().await.unwrap();
+            let mut connection = Connection::<String, Vec<u32>>::new(stream);
+
+            assert_eq!(connection.read().await.unwrap(), "ping");
+            connection.write(&vec![0; 10 * 4096]).await.unwrap();
+        });
+
+        let stream = TcpStream::connect(address).await.unwrap();
+        let mut connection = Connection::<Vec<u32>, str>::new(stream);
+
+        connection.write("ping").await.unwrap();
+        assert_eq!(connection.read().await.unwrap(), vec![0; 10 * 4096]);
+
+        server_task.await.unwrap();
+    }
 }
diff --git a/src/proto/connection.rs b/src/proto/connection.rs
deleted file mode 100644
index 0a7ee58..0000000
--- a/src/proto/connection.rs
+++ /dev/null
@@ -1,105 +0,0 @@
-use std::io;
-use std::marker::PhantomData;
-
-use bytes::BytesMut;
-use tokio::io::{AsyncReadExt, AsyncWriteExt};
-use tokio::net::TcpStream;
-
-use crate::proto::{FrameDecoder, FrameEncoder, ValueDecode, ValueEncode};
-
-#[derive(Debug)]
-pub struct Connection<ReadFrame, WriteFrame: ?Sized> {
-    stream: TcpStream,
-
-    read_buffer: BytesMut,
-
-    phantom_read: PhantomData<ReadFrame>,
-    phantom_write: PhantomData<WriteFrame>,
-}
-
-impl<ReadFrame, WriteFrame> Connection<ReadFrame, WriteFrame>
-where
-    ReadFrame: ValueDecode,
-    WriteFrame: ValueEncode + ?Sized,
-{
-    pub fn new(stream: TcpStream) -> Self {
-        Connection {
-            stream,
-            read_buffer: BytesMut::new(),
-            phantom_read: PhantomData,
-            phantom_write: PhantomData,
-        }
-    }
-
-    pub async fn read(&mut self) -> io::Result<ReadFrame> {
-        let mut decoder = FrameDecoder::new();
-
-        loop {
-            if let Some(frame) = decoder.decode_from(&mut self.read_buffer)? {
-                return Ok(frame);
-            }
-            self.stream.read_buf(&mut self.read_buffer).await?;
-        }
-    }
-
-    pub async fn write(&mut self, frame: &WriteFrame) -> io::Result<()> {
-        let mut bytes = BytesMut::new();
-        FrameEncoder::new().encode_to(frame, &mut bytes)?;
-        self.stream.write_all(bytes.as_ref()).await
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use tokio::net::{TcpListener, TcpStream};
-
-    use super::Connection;
-
-    #[tokio::test]
-    async fn ping_pong() {
-        let listener = TcpListener::bind("localhost:0").await.unwrap();
-        let address = listener.local_addr().unwrap();
-
-        let server_task = tokio::spawn(async move {
-            let (stream, _peer_address) = listener.accept().await.unwrap();
-            let mut connection = Connection::<String, str>::new(stream);
-
-            assert_eq!(connection.read().await.unwrap(), "ping");
-            connection.write("pong").await.unwrap();
-            assert_eq!(connection.read().await.unwrap(), "ping");
-            connection.write("pong").await.unwrap();
-        });
-
-        let stream = TcpStream::connect(address).await.unwrap();
-        let mut connection = Connection::<String, str>::new(stream);
-
-        connection.write("ping").await.unwrap();
-        assert_eq!(connection.read().await.unwrap(), "pong");
-        connection.write("ping").await.unwrap();
-        assert_eq!(connection.read().await.unwrap(), "pong");
-
-        server_task.await.unwrap();
-    }
-
-    #[tokio::test]
-    async fn very_large_message() {
-        let listener = TcpListener::bind("localhost:0").await.unwrap();
-        let address = listener.local_addr().unwrap();
-
-        let server_task = tokio::spawn(async move {
-            let (stream, _peer_address) = listener.accept().await.unwrap();
-            let mut connection = Connection::<String, Vec<u32>>::new(stream);
-
-            assert_eq!(connection.read().await.unwrap(), "ping");
-            connection.write(&vec![0; 10 * 4096]).await.unwrap();
-        });
-
-        let stream = TcpStream::connect(address).await.unwrap();
-        let mut connection = Connection::<Vec<u32>, str>::new(stream);
-
-        connection.write("ping").await.unwrap();
-        assert_eq!(connection.read().await.unwrap(), vec![0; 10 * 4096]);
-
-        server_task.await.unwrap();
-    }
-}
diff --git a/src/proto/mod.rs b/src/proto/mod.rs
index 4daa4ac..bcf37bc 100644
--- a/src/proto/mod.rs
+++ b/src/proto/mod.rs
@@ -1,5 +1,4 @@
 mod codec;
-mod connection;
 mod constants;
 mod handler;
 mod packet;
@@ -13,8 +12,7 @@ pub mod u32;
 mod user;
 mod value_codec;
 
-pub use self::codec::*;
-pub use self::connection::Connection;
+pub use self::codec::Connection;
 pub use self::handler::*;
 pub use self::packet::*;
 pub use self::server::{ServerRequest, ServerResponse};