diff --git a/config_proc_macro/Cargo.toml b/config_proc_macro/Cargo.toml
index 73129e68d94..ec0db49d71c 100644
--- a/config_proc_macro/Cargo.toml
+++ b/config_proc_macro/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "rustfmt-config_proc_macro"
 version = "0.3.0"
-edition = "2018"
+edition = "2021"
 description = "A collection of procedural macros for rustfmt"
 license = "Apache-2.0 OR MIT"
 categories = ["development-tools::procedural-macro-helpers"]