diff --git a/servo/components/servo_arc/Cargo.toml b/servo/components/servo_arc/Cargo.toml
index 4dda460bb743..d420360c5c36 100644
--- a/servo/components/servo_arc/Cargo.toml
+++ b/servo/components/servo_arc/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["The Servo Project Developers"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/servo/servo"
 description = "A fork of std::sync::Arc with some extra functionality and without weak references"
+edition = "2021"
 
 [lib]
 name = "servo_arc"
diff --git a/servo/components/servo_arc/lib.rs b/servo/components/servo_arc/lib.rs
index 5fbb3beab7ba..e19fd22db1ae 100644
--- a/servo/components/servo_arc/lib.rs
+++ b/servo/components/servo_arc/lib.rs
@@ -25,10 +25,6 @@
 // duplicate those here.
 #![allow(missing_docs)]
 
-#[cfg(feature = "servo")]
-extern crate serde;
-extern crate stable_deref_trait;
-
 #[cfg(feature = "servo")]
 use serde::{Deserialize, Serialize};
 use stable_deref_trait::{CloneStableDeref, StableDeref};