diff --git a/src/doc/rustc-dev-guide/ci/date-check/Cargo.toml b/src/doc/rustc-dev-guide/ci/date-check/Cargo.toml
index 95251fb12335..884f485fad54 100644
--- a/src/doc/rustc-dev-guide/ci/date-check/Cargo.toml
+++ b/src/doc/rustc-dev-guide/ci/date-check/Cargo.toml
@@ -2,7 +2,7 @@
 name = "date-check"
 version = "0.1.0"
 authors = ["Camelid <camelidcamel@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html