diff --git a/src/rooms/commands/DiscardCommand.ts b/src/rooms/commands/DiscardCommand.ts
index 05d3780..5713cf0 100644
--- a/src/rooms/commands/DiscardCommand.ts
+++ b/src/rooms/commands/DiscardCommand.ts
@@ -44,7 +44,7 @@ export class DiscardCommand extends Command<CardGameState, { client: Client, car
         }
         this.state.cards.clear();
         //停止出牌计时, 并更新player.extraTime;
-        if (this.room.mainClock && this.room.mainClock.active) {
+        if (this.room.mainClock?.active) {
             let maxTime = singleton(GameEnv).maxDiscardTime * 1000;
             let count = this.room.mainClock.elapsedTime - maxTime;
             let newCount = player.extraTime - count;
diff --git a/src/rooms/commands/EatConfirmCommand.ts b/src/rooms/commands/EatConfirmCommand.ts
index 541b2d3..02745de 100644
--- a/src/rooms/commands/EatConfirmCommand.ts
+++ b/src/rooms/commands/EatConfirmCommand.ts
@@ -32,7 +32,7 @@ export class EatConfirmCommand extends Command<CardGameState, { timeUp: boolean
         }
         if (giveUpCount >= playerCount) {
             // 所有人都放弃了, 则取消定时, 直接进入下一轮
-            if (this.room.mainClock && this.room.mainClock.active) {
+            if (this.room.mainClock?.active) {
                 this.room.mainClock.clear();
             }
             return [new TurnEndCommand()];
@@ -67,7 +67,7 @@ export class EatConfirmCommand extends Command<CardGameState, { timeUp: boolean
         // 吃牌逻辑
         if (player != null && (isFirst || timeUp)) {
             // 如果有吃牌计时的话,停止吃牌计时
-            if (this.room.mainClock && this.room.mainClock.active) {
+            if (this.room.mainClock?.active) {
                 this.room.mainClock.clear();
             }
             for (let id of cards) {
diff --git a/src/rooms/commands/SelectPetCommand.ts b/src/rooms/commands/SelectPetCommand.ts
index 4e6493b..4cea94f 100644
--- a/src/rooms/commands/SelectPetCommand.ts
+++ b/src/rooms/commands/SelectPetCommand.ts
@@ -72,7 +72,7 @@ export class SelectPetCommand extends Command<CardGameState, {client: Client,
             return;
         }
         //停止选随从计时, 并更新player.extraTime;
-        if (this.room.mainClock && this.room.mainClock.active) {
+        if (this.room.mainClock?.active) {
             let count = this.room.mainClock.elapsedTime - singleton(GameEnv).playerActTime * 1000;
             let newCount = player.extraTime - count;
             player.extraTime = Math.max(newCount, 0);