diff --git a/2021/day1/day1_rs/src/main.rs b/2021/day1/day1_rs/src/main.rs
index 32e167e..063822d 100644
--- a/2021/day1/day1_rs/src/main.rs
+++ b/2021/day1/day1_rs/src/main.rs
@@ -1,3 +1,4 @@
+#![warn(clippy::pedantic)]
 use itertools::Itertools;
 use std::io::{self, BufRead};
 
@@ -18,7 +19,7 @@ fn main() {
         count_increasing(
             numbers
                 .windows(3)
-                .map(|window| -> usize { window.iter().sum() })
+                .map(|window| window.iter().sum::<usize>())
         )
     );
 }