diff --git a/src/connection.rs b/src/connection.rs
index 343473af..d91a0c6d 100644
--- a/src/connection.rs
+++ b/src/connection.rs
@@ -11,7 +11,6 @@ use futures_channel::oneshot::{channel, Sender};
 use futures_core::{future::BoxFuture, stream::BoxStream};
 use futures_util::{stream::StreamExt, TryFutureExt};
 use std::{
-    io,
     ops::{Deref, DerefMut},
     sync::{
         atomic::{AtomicBool, Ordering},
@@ -38,10 +37,10 @@ pub trait RawConnection: Send {
     /// and clean up not fully closed connections.
     ///
     /// It is safe to close an already closed connection.
-    fn close<'c>(&'c mut self) -> BoxFuture<'c, Result<(), Error>>;
+    fn close(&mut self) -> BoxFuture<'_, Result<(), Error>>;
 
     /// Verifies a connection to the database is still alive.
-    fn ping<'c>(&'c mut self) -> BoxFuture<'c, Result<(), Error>> {
+    fn ping(&mut self) -> BoxFuture<'_, Result<(), Error>> {
         Box::pin(
             self.execute(
                 "SELECT 1",
diff --git a/src/executor.rs b/src/executor.rs
index ef6cca3c..289ef7c2 100644
--- a/src/executor.rs
+++ b/src/executor.rs
@@ -1,11 +1,5 @@
-use crate::{
-    backend::Backend,
-    error::Error,
-    query::{IntoQueryParameters, QueryParameters},
-    row::FromSqlRow,
-};
+use crate::{backend::Backend, error::Error, query::IntoQueryParameters, row::FromSqlRow};
 use futures_core::{future::BoxFuture, stream::BoxStream};
-use std::io;
 
 pub trait Executor: Send {
     type Backend: Backend;
diff --git a/src/io/buf.rs b/src/io/buf.rs
index 566bacfb..76b7f416 100644
--- a/src/io/buf.rs
+++ b/src/io/buf.rs
@@ -1,6 +1,6 @@
 use byteorder::ByteOrder;
 use memchr::memchr;
-use std::{convert::TryInto, io, mem::size_of, str};
+use std::{io, str};
 
 pub trait Buf {
     fn advance(&mut self, cnt: usize);
@@ -91,11 +91,11 @@ impl<'a> Buf for &'a [u8] {
 
     fn get_uint_lenenc<T: ByteOrder>(&mut self) -> io::Result<u64> {
         Ok(match self.get_u8()? {
-            0xFC => self.get_u16::<T>()? as u64,
-            0xFD => self.get_u24::<T>()? as u64,
-            0xFE => self.get_u64::<T>()? as u64,
+            0xFC => u64::from(self.get_u16::<T>()?),
+            0xFD => u64::from(self.get_u24::<T>()?),
+            0xFE => self.get_u64::<T>()?,
             // ? 0xFF => panic!("int<lenenc> unprocessable first byte 0xFF"),
-            value => value as u64,
+            value => u64::from(value),
         })
     }
 
diff --git a/src/io/buf_mut.rs b/src/io/buf_mut.rs
index f44a30c3..c1fb159f 100644
--- a/src/io/buf_mut.rs
+++ b/src/io/buf_mut.rs
@@ -1,6 +1,5 @@
 use byteorder::ByteOrder;
-use memchr::memchr;
-use std::{io, mem::size_of, str, u16, u32, u8};
+use std::{str, u16, u32, u8};
 
 pub trait BufMut {
     fn advance(&mut self, cnt: usize);
@@ -82,11 +81,11 @@ impl BufMut for Vec<u8> {
             // Integer value is encoded in the next 8 bytes (9 bytes total)
             self.push(0xFE);
             self.put_u64::<T>(value);
-        } else if value > u16::MAX as _ {
+        } else if value > u64::from(u16::MAX) {
             // Integer value is encoded in the next 3 bytes (4 bytes total)
             self.push(0xFD);
             self.put_u24::<T>(value as u32);
-        } else if value > u8::MAX as _ {
+        } else if value > u64::from(u8::MAX) {
             // Integer value is encoded in the next 2 bytes (3 bytes total)
             self.push(0xFC);
             self.put_u16::<T>(value as u16);
diff --git a/src/io/buf_stream.rs b/src/io/buf_stream.rs
index b90a78e5..5d7775e8 100644
--- a/src/io/buf_stream.rs
+++ b/src/io/buf_stream.rs
@@ -23,7 +23,7 @@ where
         Self {
             stream,
             stream_eof: false,
-            wbuf: Vec::with_capacity(1 * 1024),
+            wbuf: Vec::with_capacity(1024),
             rbuf: BytesMut::with_capacity(8 * 1024),
         }
     }
@@ -39,7 +39,7 @@ where
 
     #[inline]
     pub async fn flush(&mut self) -> io::Result<()> {
-        if self.wbuf.len() > 0 {
+        if !self.wbuf.is_empty() {
             self.stream.write_all(&self.wbuf).await?;
             self.wbuf.clear();
         }
diff --git a/src/lib.rs b/src/lib.rs
index b1cf132d..2a959f5a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,18 +1,14 @@
-#![cfg_attr(test, feature(test))]
-#![allow(clippy::needless_lifetimes)]
-#![allow(unused)]
-
-#[cfg(test)]
-extern crate test;
-
 #[macro_use]
 mod macros;
 
+#[cfg(any(feature = "postgres", feature = "mariadb"))]
 #[macro_use]
 mod io;
 
 mod backend;
 pub mod deserialize;
+
+#[cfg(any(feature = "postgres", feature = "mariadb"))]
 mod url;
 
 #[macro_use]
diff --git a/src/mariadb/mod.rs b/src/mariadb/mod.rs
index 2b46ff09..586c6720 100644
--- a/src/mariadb/mod.rs
+++ b/src/mariadb/mod.rs
@@ -1,3 +1,6 @@
+// TODO: Remove after acitve development
+#![allow(ununsed)]
+
 // mod backend;
 // mod connection;
 mod protocol;
diff --git a/src/pool.rs b/src/pool.rs
index bcf73470..18c954ff 100644
--- a/src/pool.rs
+++ b/src/pool.rs
@@ -1,17 +1,12 @@
 use crate::{
-    backend::Backend,
-    connection::RawConnection,
-    error::Error,
-    executor::Executor,
-    query::{IntoQueryParameters, QueryParameters},
-    row::FromSqlRow,
+    backend::Backend, connection::RawConnection, error::Error, executor::Executor,
+    query::IntoQueryParameters, row::FromSqlRow,
 };
 use crossbeam_queue::{ArrayQueue, SegQueue};
 use futures_channel::oneshot;
 use futures_core::{future::BoxFuture, stream::BoxStream};
 use futures_util::stream::StreamExt;
 use std::{
-    io,
     ops::{Deref, DerefMut},
     sync::{
         atomic::{AtomicUsize, Ordering},
@@ -244,6 +239,8 @@ where
     DB: Backend,
 {
     live: Live<DB>,
+    // TODO: Implement idle connection timeouts
+    #[allow(unused)]
     since: Instant,
 }
 
@@ -252,5 +249,7 @@ where
     DB: Backend,
 {
     raw: DB::RawConnection,
+    // TODO: Implement live connection timeouts
+    #[allow(unused)]
     since: Instant,
 }
diff --git a/src/postgres/connection.rs b/src/postgres/connection.rs
index 7bbe633c..fddc298f 100644
--- a/src/postgres/connection.rs
+++ b/src/postgres/connection.rs
@@ -4,22 +4,13 @@ use super::{
 };
 use crate::{
     connection::RawConnection,
-    error::Error,
     io::{Buf, BufStream},
-    query::QueryParameters,
     url::Url,
 };
 use byteorder::NetworkEndian;
 use futures_core::{future::BoxFuture, stream::BoxStream};
-use std::{
-    io,
-    net::{IpAddr, Shutdown, SocketAddr},
-    sync::atomic::{AtomicU64, Ordering},
-};
-use tokio::{
-    io::{AsyncReadExt, AsyncWriteExt},
-    net::TcpStream,
-};
+use std::io;
+use tokio::net::TcpStream;
 
 pub struct PostgresRawConnection {
     stream: BufStream<TcpStream>,
diff --git a/src/postgres/mod.rs b/src/postgres/mod.rs
index 33a4a0f7..40e13925 100644
--- a/src/postgres/mod.rs
+++ b/src/postgres/mod.rs
@@ -28,7 +28,7 @@ mod tests {
 
     #[tokio::test]
     async fn it_pings() {
-        let mut conn = Connection::<Postgres>::establish(DATABASE_URL)
+        let conn = Connection::<Postgres>::establish(DATABASE_URL)
             .await
             .unwrap();
 
diff --git a/src/postgres/protocol/bind.rs b/src/postgres/protocol/bind.rs
index 5ed47d4a..b48ad9c8 100644
--- a/src/postgres/protocol/bind.rs
+++ b/src/postgres/protocol/bind.rs
@@ -1,6 +1,6 @@
 use super::Encode;
 use crate::io::BufMut;
-use byteorder::{BigEndian, ByteOrder, NetworkEndian};
+use byteorder::{ByteOrder, NetworkEndian};
 
 pub struct Bind<'a> {
     /// The name of the destination portal (an empty string selects the unnamed portal).
diff --git a/src/postgres/protocol/close.rs b/src/postgres/protocol/close.rs
index 709b6bc2..6fc93b3c 100644
--- a/src/postgres/protocol/close.rs
+++ b/src/postgres/protocol/close.rs
@@ -34,7 +34,7 @@ impl Encode for Close<'_> {
 
 #[cfg(test)]
 mod test {
-    use super::{BufMut, Close, CloseKind, Encode};
+    use super::{Close, CloseKind, Encode};
 
     #[test]
     fn it_encodes_close_portal() {
diff --git a/src/postgres/protocol/data_row.rs b/src/postgres/protocol/data_row.rs
index abd96eb7..a7c356e4 100644
--- a/src/postgres/protocol/data_row.rs
+++ b/src/postgres/protocol/data_row.rs
@@ -82,7 +82,6 @@ impl Debug for DataRow {
 #[cfg(test)]
 mod tests {
     use super::{DataRow, Decode};
-    use std::io;
 
     const DATA_ROW: &[u8] = b"\0\x03\0\0\0\x011\0\0\0\x012\0\0\0\x013";
 
diff --git a/src/postgres/protocol/describe.rs b/src/postgres/protocol/describe.rs
index a290426a..6df51885 100644
--- a/src/postgres/protocol/describe.rs
+++ b/src/postgres/protocol/describe.rs
@@ -31,7 +31,7 @@ impl Encode for Describe<'_> {
 
 #[cfg(test)]
 mod test {
-    use super::{BufMut, Describe, DescribeKind, Encode};
+    use super::{Describe, DescribeKind, Encode};
 
     #[test]
     fn it_encodes_describe_portal() {
diff --git a/src/postgres/protocol/message.rs b/src/postgres/protocol/message.rs
index c1df45da..2a854723 100644
--- a/src/postgres/protocol/message.rs
+++ b/src/postgres/protocol/message.rs
@@ -1,10 +1,7 @@
 use super::{
-    Authentication, BackendKeyData, CommandComplete, DataRow, Decode, NotificationResponse,
+    Authentication, BackendKeyData, CommandComplete, DataRow, NotificationResponse,
     ParameterDescription, ParameterStatus, ReadyForQuery, Response,
 };
-use byteorder::{BigEndian, ByteOrder};
-use bytes::BytesMut;
-use std::io;
 
 #[derive(Debug)]
 #[repr(u8)]
diff --git a/src/postgres/protocol/notification_response.rs b/src/postgres/protocol/notification_response.rs
index cef5d34a..2aa07494 100644
--- a/src/postgres/protocol/notification_response.rs
+++ b/src/postgres/protocol/notification_response.rs
@@ -66,7 +66,6 @@ impl Decode for NotificationResponse {
 #[cfg(test)]
 mod tests {
     use super::{Decode, NotificationResponse};
-    use std::io;
 
     const NOTIFICATION_RESPONSE: &[u8] = b"\x34\x20\x10\x02TEST-CHANNEL\0THIS IS A TEST\0";
 
diff --git a/src/postgres/protocol/parameter_description.rs b/src/postgres/protocol/parameter_description.rs
index 3b3328ec..ef122b55 100644
--- a/src/postgres/protocol/parameter_description.rs
+++ b/src/postgres/protocol/parameter_description.rs
@@ -13,7 +13,7 @@ impl Decode for ParameterDescription {
         let cnt = buf.get_u16::<NetworkEndian>()? as usize;
         let mut ids = Vec::with_capacity(cnt);
 
-        for i in 0..cnt {
+        for _ in 0..cnt {
             ids.push(buf.get_u32::<NetworkEndian>()?);
         }
 
@@ -26,7 +26,6 @@ impl Decode for ParameterDescription {
 #[cfg(test)]
 mod test {
     use super::{Decode, ParameterDescription};
-    use std::io;
 
     #[test]
     fn it_decodes_parameter_description() {
diff --git a/src/postgres/protocol/parameter_status.rs b/src/postgres/protocol/parameter_status.rs
index b80afae1..3815c7f7 100644
--- a/src/postgres/protocol/parameter_status.rs
+++ b/src/postgres/protocol/parameter_status.rs
@@ -49,7 +49,7 @@ impl Decode for ParameterStatus {
     }
 }
 
-impl fmt::Debug for ParameterStatus {
+impl Debug for ParameterStatus {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("ParameterStatus")
             .field("name", &self.name())
diff --git a/src/postgres/protocol/query.rs b/src/postgres/protocol/query.rs
index 39a64687..9938f570 100644
--- a/src/postgres/protocol/query.rs
+++ b/src/postgres/protocol/query.rs
@@ -17,7 +17,7 @@ impl Encode for Query<'_> {
 
 #[cfg(test)]
 mod tests {
-    use super::{BufMut, Encode, Query};
+    use super::{Encode, Query};
 
     const QUERY_SELECT_1: &[u8] = b"Q\0\0\0\rSELECT 1\0";
 
diff --git a/src/postgres/protocol/startup_message.rs b/src/postgres/protocol/startup_message.rs
index b49f796f..2c29c6e1 100644
--- a/src/postgres/protocol/startup_message.rs
+++ b/src/postgres/protocol/startup_message.rs
@@ -29,7 +29,7 @@ impl Encode for StartupMessage<'_> {
 
 #[cfg(test)]
 mod tests {
-    use super::{BufMut, Encode, StartupMessage};
+    use super::{Encode, StartupMessage};
 
     const STARTUP_MESSAGE: &[u8] = b"\0\0\0)\0\x03\0\0user\0postgres\0database\0postgres\0\0";
 
diff --git a/src/postgres/query.rs b/src/postgres/query.rs
index 44f6b94b..cbbb6304 100644
--- a/src/postgres/query.rs
+++ b/src/postgres/query.rs
@@ -1,4 +1,4 @@
-use super::{protocol, Postgres, PostgresRawConnection};
+use super::Postgres;
 use crate::{
     io::BufMut,
     query::QueryParameters,
diff --git a/src/query.rs b/src/query.rs
index 0a864c46..6efbffd2 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -1,9 +1,4 @@
-use crate::{
-    backend::Backend, error::Error, executor::Executor, row::FromSqlRow, serialize::ToSql,
-    types::HasSqlType,
-};
-use futures_core::{future::BoxFuture, stream::BoxStream};
-use std::io;
+use crate::{backend::Backend, serialize::ToSql, types::HasSqlType};
 
 pub trait QueryParameters: Send {
     type Backend: Backend;
diff --git a/src/sql.rs b/src/sql.rs
index 79fad1e0..24128049 100644
--- a/src/sql.rs
+++ b/src/sql.rs
@@ -3,7 +3,6 @@ use crate::{
     serialize::ToSql, types::HasSqlType,
 };
 use futures_core::{future::BoxFuture, stream::BoxStream};
-use std::io;
 
 pub struct SqlQuery<'q, DB>
 where
@@ -72,7 +71,7 @@ where
 
 /// Construct a full SQL query using raw SQL.
 #[inline]
-pub fn query<'q, DB>(query: &'q str) -> SqlQuery<'q, DB>
+pub fn query<DB>(query: &str) -> SqlQuery<'_, DB>
 where
     DB: Backend,
 {
diff --git a/src/types.rs b/src/types.rs
index 23105b3b..f3210b93 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,5 +1,3 @@
-use crate::backend::Backend;
-
 /// Information about how a backend stores metadata about
 /// given SQL types.
 pub trait TypeMetadata {