diff --git a/apps/server/src/domains/game/application/useCases/pingUseCase.ts b/apps/server/src/domains/game/application/useCases/pingUseCase.ts
index c357d66..ef302f3 100644
--- a/apps/server/src/domains/game/application/useCases/pingUseCase.ts
+++ b/apps/server/src/domains/game/application/useCases/pingUseCase.ts
@@ -2,10 +2,11 @@
  * pingUseCase
  * PING受信時に時刻情報付きPONGを返して遅延計測を支援する
  */
+import type { PingPayload } from "@repo/shared";
 import type { GameOutputPort } from "../ports/gameUseCasePorts";
 
 type PingUseCaseParams = {
-  clientTime: number;
+  clientTime: PingPayload;
   output: Pick<GameOutputPort, "publishPongToSocket">;
 };
 
diff --git a/apps/server/src/network/validation/socketPayloadValidators.ts b/apps/server/src/network/validation/socketPayloadValidators.ts
index beba0ee..0345b37 100644
--- a/apps/server/src/network/validation/socketPayloadValidators.ts
+++ b/apps/server/src/network/validation/socketPayloadValidators.ts
@@ -3,6 +3,7 @@
  * ソケット受信ペイロードの型ガードを提供する
  */
 import type { playerTypes, roomTypes } from "@repo/shared";
+import type { PingPayload } from "@repo/shared";
 
 const isFiniteNumber = (value: unknown): value is number => {
   return typeof value === "number" && Number.isFinite(value);
@@ -13,7 +14,7 @@
 };
 
 /** PINGイベントのペイロードが数値であるか判定する */
-export const isPingPayload = (value: unknown): value is number => {
+export const isPingPayload = (value: unknown): value is PingPayload => {
   return isFiniteNumber(value);
 };
 
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index f832b8e..9b04bc1 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -13,6 +13,7 @@
 	GameStartPayload,
 	MovePayload,
 	NewPlayerPayload,
+	PingPayload,
 	PongPayload,
 	RemovePlayerPayload,
 	UpdateMapCellsPayload,
diff --git a/packages/shared/src/protocol/events.ts b/packages/shared/src/protocol/events.ts
index 5cb3b39..e6221bb 100644
--- a/packages/shared/src/protocol/events.ts
+++ b/packages/shared/src/protocol/events.ts
@@ -56,6 +56,9 @@
 /** MOVE イベントで送受信する移動入力情報 */
 export type MovePayload = PlayerMovePayload;
 
+/** PING イベントで送受信する時刻同期リクエスト */
+export type PingPayload = number;
+
 /** PONG イベントで送受信する時刻同期レスポンス */
 export type PongPayload = {
   clientTime: number;