diff --git a/backend/src/shengji_handler.rs b/backend/src/shengji_handler.rs
index 40f6225..2c01492 100644
--- a/backend/src/shengji_handler.rs
+++ b/backend/src/shengji_handler.rs
@@ -190,7 +190,7 @@ async fn register_user<S: Storage<VersionedGame, E>, E: std::fmt::Debug + Send>(
             let mut clients_to_disconnect = vec![];
             let clients = associated_websockets
                 .entry(assigned_player_id)
-                .or_insert_with(Vec::new);
+                .or_default();
             // If the same user joined before, remove the previous entries
             // from the state-store.
             if !g.allows_multiple_sessions_per_user() {
diff --git a/mechanics/src/ordered_card.rs b/mechanics/src/ordered_card.rs
index 02eb5e4..4bb4292 100644
--- a/mechanics/src/ordered_card.rs
+++ b/mechanics/src/ordered_card.rs
@@ -104,7 +104,7 @@ pub fn subsequent_decomposition_ordering(
         let mut decomp = full_decomposition_ordering(len);
         decomp.reverse();
         while let Some(v) = decomp.pop() {
-            if v.len() == 1 && v.get(0) == Some(adj_req) {
+            if v.len() == 1 && v.first() == Some(adj_req) {
                 break;
             }
         }
diff --git a/mechanics/src/trick.rs b/mechanics/src/trick.rs
index cc9529b..2e466b6 100644
--- a/mechanics/src/trick.rs
+++ b/mechanics/src/trick.rs
@@ -716,8 +716,7 @@ impl Trick {
                 points: all_card_points,
                 largest_trick_unit_size: tf.units.iter().map(|u| u.size()).max().unwrap_or(0),
                 failed_throw_size: self
-                    .played_cards
-                    .get(0)
+                    .played_cards.first()
                     .ok_or(TrickError::OutOfOrder)?
                     .bad_throw_cards
                     .len(),