diff --git a/src/admin/room/commands.rs b/src/admin/room/commands.rs
index 41cc427f..ae865c27 100644
--- a/src/admin/room/commands.rs
+++ b/src/admin/room/commands.rs
@@ -180,7 +180,7 @@ pub(super) async fn purge_all_sync_tokens(
 		total_rooms_checked = total_rooms_checked.saturating_add(1);
 
 		// Log progress periodically
-		if total_rooms_checked % 100 == 0 || total_rooms_checked == total_rooms {
+		if total_rooms_checked.is_multiple_of(100) || total_rooms_checked == total_rooms {
 			info!(
 				"Progress: {}/{} rooms checked, {} tokens {}",
 				total_rooms_checked,
diff --git a/src/core/config/mod.rs b/src/core/config/mod.rs
index 93c45af9..6ecd7113 100644
--- a/src/core/config/mod.rs
+++ b/src/core/config/mod.rs
@@ -2576,7 +2576,7 @@ fn default_roomid_spacehierarchy_cache_capacity() -> u32 {
 	parallelism_scaled_u32(500).clamp(100, 12000)
 }
 
-fn default_dns_cache_entries() -> u32 { 327680 }
+fn default_dns_cache_entries() -> u32 { 327_680 }
 
 fn default_dns_min_ttl() -> u64 { 60 * 180 }
 
@@ -2784,17 +2784,23 @@ fn default_admin_log_capture() -> String {
 
 fn default_admin_room_tag() -> String { "m.server_notice".to_owned() }
 
+#[must_use]
 #[allow(clippy::as_conversions, clippy::cast_precision_loss)]
 pub fn parallelism_scaled_f64(val: f64) -> f64 { val * (sys::available_parallelism() as f64) }
 
+#[must_use]
+#[allow(clippy::as_conversions, clippy::cast_possible_truncation)]
 pub fn parallelism_scaled_u32(val: u32) -> u32 {
 	val.saturating_mul(sys::available_parallelism() as u32)
 }
 
+#[must_use]
+#[allow(clippy::as_conversions, clippy::cast_possible_truncation, clippy::cast_possible_wrap)]
 pub fn parallelism_scaled_i32(val: i32) -> i32 {
 	val.saturating_mul(sys::available_parallelism() as i32)
 }
 
+#[must_use]
 pub fn parallelism_scaled(val: usize) -> usize {
 	val.saturating_mul(sys::available_parallelism())
 }
diff --git a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
index cd6d1815..8ec990f5 100644
--- a/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
+++ b/src/service/rooms/event_handler/upgrade_outlier_pdu.rs
@@ -197,13 +197,13 @@ where
 		.await;
 	extremities.push(incoming_pdu.event_id().to_owned());
 
-	if extremities.len() == 0 {
+	if extremities.is_empty() {
 		info!(
 			"Retained zero extremities when upgrading outlier PDU to timeline PDU with {} \
 			 previous events, event id: {}",
 			incoming_pdu.prev_events.len(),
 			incoming_pdu.event_id
-		)
+		);
 	}
 
 	debug!(