diff --git a/scripts/grade-hw1.sh b/scripts/grade-hw1.sh
index eaf90c1..dfac604 100644
--- a/scripts/grade-hw1.sh
+++ b/scripts/grade-hw1.sh
@@ -4,7 +4,7 @@
 set -e
 
 # Run lints.
-cargo fmt --all -- --check
+cargo fmt --all -- --check # run `cargo fmt` to auto-correct format.
 cargo clippy
 
 # Run tests.