diff --git a/src/solvers/lobby.rs b/src/solvers/lobby.rs
index f721023..f393eb1 100644
--- a/src/solvers/lobby.rs
+++ b/src/solvers/lobby.rs
@@ -9,7 +9,7 @@ impl Lobby {
 
     fn largest_joltage(bank: &str, max_batteries: usize) -> u64 {
         let mut best = vec![0_u8; max_batteries];
-        for (i, d) in bank.bytes().map(|c| c - '0' as u8).enumerate() {
+        for (i, d) in bank.bytes().map(|c| c - b'0').enumerate() {
             let mut fill_index = max_batteries;
             let skip = (max_batteries + i).saturating_sub(bank.len());
             for (j, b) in best.iter_mut().skip(skip).enumerate() {