diff --git a/src/bin/main.rs b/src/bin/main.rs
index 4b4aa42d935..1bcc5c0dada 100644
--- a/src/bin/main.rs
+++ b/src/bin/main.rs
@@ -121,7 +121,7 @@ fn make_opts() -> Options {
          found reverts to the input file path",
         "[Path for the configuration file]",
     );
-    opts.optopt("", "edition", "Rust edition to use", "[2015|2018]");
+    opts.optopt("", "edition", "Rust edition to use", "[2015|2018|2021]");
     opts.optopt(
         "",
         "color",