diff --git a/Cargo.toml b/Cargo.toml
index ca66a7c66..507193a29 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,6 @@
 [package]
 name = "xattr"
+edition = "2021"
 version = "0.2.3"
 authors = ["Steven Allen <steven@stebalien.com>"]
 description = "unix extended filesystem attributes"
diff --git a/src/lib.rs b/src/lib.rs
index bf00b37f3..f80e71da2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+#![allow(clippy::comparison_chain)]
 //! A pure-Rust library to manage extended attributes.
 //!
 //! It provides support for manipulating extended attributes
@@ -25,8 +26,6 @@
 //! }
 //! ```
 
-extern crate libc;
-
 mod error;
 mod sys;
 mod util;
diff --git a/src/sys/linux_macos/mod.rs b/src/sys/linux_macos/mod.rs
index c0e86fe31..7cca3e083 100644
--- a/src/sys/linux_macos/mod.rs
+++ b/src/sys/linux_macos/mod.rs
@@ -19,7 +19,7 @@ use std::path::Path;
 
 use libc::{c_char, c_void, size_t};
 
-use util::{allocate_loop, name_to_c, path_to_c};
+use crate::util::{allocate_loop, name_to_c, path_to_c};
 
 /// An iterator over a set of extended attributes names.
 pub struct XAttrs {
diff --git a/src/sys/mod.rs b/src/sys/mod.rs
index 4724826b5..756a31605 100644
--- a/src/sys/mod.rs
+++ b/src/sys/mod.rs
@@ -9,6 +9,7 @@ macro_rules! platforms {
             pub use self::$module::*;
 
             #[cfg(any($(target_os = $platform),*))]
+            #[allow(deprecated)] // other platforms still use ENOATTR
             pub const ENOATTR: ::libc::c_int = ::libc::ENOATTR;
         )*
 
diff --git a/src/util.rs b/src/util.rs
index d107694b6..ea80062e6 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -10,7 +10,7 @@ use libc::{ssize_t, ERANGE};
 // Need to use this one as libc only defines this on supported platforms. Given
 // that we want to at least compile on unsupported platforms, we define this in
 // our platform-specific modules.
-use sys::ENOATTR;
+use crate::sys::ENOATTR;
 
 #[allow(dead_code)]
 pub fn name_to_c(name: &OsStr) -> io::Result<CString> {
diff --git a/tests/main.rs b/tests/main.rs
index 0c4367862..c93987e3c 100644
--- a/tests/main.rs
+++ b/tests/main.rs
@@ -1,6 +1,3 @@
-extern crate tempfile;
-extern crate xattr;
-
 use std::collections::BTreeSet;
 use std::ffi::OsStr;
 use xattr::FileExt;
@@ -98,14 +95,16 @@ fn test_multi() {
         OsStr::new("user.test1"),
         OsStr::new("user.test2"),
         OsStr::new("user.test3"),
-    ].iter()
-        .cloned()
-        .collect();
+    ]
+    .iter()
+    .cloned()
+    .collect();
 
     for it in &items {
         tmp.set_xattr(it, b"value").unwrap();
     }
-    for it in tmp.list_xattr()
+    for it in tmp
+        .list_xattr()
         .unwrap()
         .filter(|x| x.as_bytes().starts_with(&*b"user."))
     {