diff --git a/app/api/src/main/kotlin/com/xorker/draw/user/UserController.kt b/app/api/src/main/kotlin/com/xorker/draw/user/UserController.kt
index a07688df..555ae88e 100644
--- a/app/api/src/main/kotlin/com/xorker/draw/user/UserController.kt
+++ b/app/api/src/main/kotlin/com/xorker/draw/user/UserController.kt
@@ -1,5 +1,6 @@
 package com.xorker.draw.user
 
+import com.xorker.draw.exception.NotFoundUserException
 import com.xorker.draw.support.auth.NeedLogin
 import com.xorker.draw.support.auth.PrincipalUser
 import com.xorker.draw.user.dto.UpdateUserRequest
@@ -7,6 +8,7 @@ import com.xorker.draw.user.dto.UserDetailResponse
 import com.xorker.draw.user.dto.UserResponse
 import com.xorker.draw.user.dto.toResponse
 import io.swagger.v3.oas.annotations.Operation
+import io.swagger.v3.oas.annotations.Parameter
 import io.swagger.v3.oas.annotations.tags.Tag
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PatchMapping
@@ -22,9 +24,10 @@ class UserController(
     @GetMapping("/api/v1/user")
     @NeedLogin
     fun getUserDetail(
-        user: PrincipalUser,
+        @Parameter(hidden = true) user: PrincipalUser,
     ): UserDetailResponse {
-        return userUseCase.getUserDetail(user.userId).toResponse()
+        val userInfo = userUseCase.getUserDetail(user.userId) ?: throw NotFoundUserException
+        return userInfo.toResponse()
     }
 
     @Operation(summary = "유저 정보 수정")
diff --git a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/BaseWebSocketHandler.kt b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/BaseWebSocketHandler.kt
index 0c40e8f5..cb8504d6 100644
--- a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/BaseWebSocketHandler.kt
+++ b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/BaseWebSocketHandler.kt
@@ -12,6 +12,7 @@ import com.xorker.draw.support.logging.logger
 import com.xorker.draw.support.logging.registerRequestId
 import com.xorker.draw.user.User
 import com.xorker.draw.user.UserId
+import com.xorker.draw.user.UserUseCase
 import com.xorker.draw.websocket.exception.WebSocketExceptionHandler
 import com.xorker.draw.websocket.message.request.RequestAction
 import com.xorker.draw.websocket.message.request.WebSocketRequest
@@ -36,6 +37,7 @@ internal abstract class BaseWebSocketHandler(
     private val tokenUseCase: TokenUseCase,
     private val gameUseCase: MafiaGameUseCase,
     private val webSocketExceptionHandler: WebSocketExceptionHandler,
+    private val userUseCase: UserUseCase,
 ) : TextWebSocketHandler() {
     private val logger = logger()
 
@@ -154,7 +156,13 @@ internal abstract class BaseWebSocketHandler(
 
     private fun getUser(session: WebSocketSession): User? {
         val userId = getUserId(session) ?: return null
-        val encodedNickname = session.getHeader(HEADER_NICKNAME) ?: return null
+        val encodedNickname = session.getHeader(HEADER_NICKNAME)
+        val user = userUseCase.getUserDetail(userId)
+
+        if (user?.name != null) return User(userId, user.name!!)
+
+        if (encodedNickname == null) throw InvalidRequestValueException
+
         val nickname = URLDecoder.decode(encodedNickname, StandardCharsets.UTF_8.toString())
 
         return User(userId, nickname)
diff --git a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/QuickWebSocketHandler.kt b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/QuickWebSocketHandler.kt
index 924535f4..f3565e71 100644
--- a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/QuickWebSocketHandler.kt
+++ b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/QuickWebSocketHandler.kt
@@ -5,6 +5,7 @@ import com.xorker.draw.auth.token.TokenUseCase
 import com.xorker.draw.mafia.MafiaGameUseCase
 import com.xorker.draw.mafia.UserConnectionUseCase
 import com.xorker.draw.mafia.WaitingQueueUseCase
+import com.xorker.draw.user.UserUseCase
 import com.xorker.draw.websocket.WebSocketRouter
 import com.xorker.draw.websocket.exception.WebSocketExceptionHandler
 import com.xorker.draw.websocket.message.request.WebSocketRequest
@@ -22,6 +23,7 @@ internal class QuickWebSocketHandler(
     tokenUseCase: TokenUseCase,
     gameUseCase: MafiaGameUseCase,
     webSocketExceptionHandler: WebSocketExceptionHandler,
+    userUseCase: UserUseCase,
     private val userConnectionUseCase: UserConnectionUseCase,
     private val router: WebSocketRouter,
     private val waitingQueueUseCase: WaitingQueueUseCase,
@@ -32,6 +34,7 @@ internal class QuickWebSocketHandler(
     tokenUseCase,
     gameUseCase,
     webSocketExceptionHandler,
+    userUseCase,
 ) {
     override fun afterConnect(session: Session) {
         waitingQueueUseCase.enqueue(session.user, session.locale)
diff --git a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/RoomWebSocketHandler.kt b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/RoomWebSocketHandler.kt
index f4a64e7e..08c28819 100644
--- a/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/RoomWebSocketHandler.kt
+++ b/app/websocket/src/main/kotlin/com/xorker/draw/websocket/handler/RoomWebSocketHandler.kt
@@ -5,6 +5,7 @@ import com.xorker.draw.auth.token.TokenUseCase
 import com.xorker.draw.mafia.MafiaGameUseCase
 import com.xorker.draw.mafia.UserConnectionUseCase
 import com.xorker.draw.room.RoomId
+import com.xorker.draw.user.UserUseCase
 import com.xorker.draw.websocket.WebSocketRouter
 import com.xorker.draw.websocket.exception.WebSocketExceptionHandler
 import com.xorker.draw.websocket.message.request.WebSocketRequest
@@ -22,6 +23,7 @@ internal class RoomWebSocketHandler(
     tokenUseCase: TokenUseCase,
     gameUseCase: MafiaGameUseCase,
     webSocketExceptionHandler: WebSocketExceptionHandler,
+    userUseCase: UserUseCase,
     private val userConnectionUseCase: UserConnectionUseCase,
     private val router: WebSocketRouter,
 ) : BaseWebSocketHandler(
@@ -31,6 +33,7 @@ internal class RoomWebSocketHandler(
     tokenUseCase,
     gameUseCase,
     webSocketExceptionHandler,
+    userUseCase,
 ) {
     override fun afterConnect(session: Session) {
         userConnectionUseCase.connectUser(
diff --git a/core/src/main/kotlin/com/xorker/draw/user/UserService.kt b/core/src/main/kotlin/com/xorker/draw/user/UserService.kt
index d952a9ba..ffd8b077 100644
--- a/core/src/main/kotlin/com/xorker/draw/user/UserService.kt
+++ b/core/src/main/kotlin/com/xorker/draw/user/UserService.kt
@@ -1,14 +1,13 @@
 package com.xorker.draw.user
 
-import com.xorker.draw.exception.NotFoundUserException
 import org.springframework.stereotype.Service
 
 @Service
 internal class UserService(
     private val userRepository: UserRepository,
 ) : UserUseCase {
-    override fun getUserDetail(userId: UserId): UserDetail {
-        val userInfo = userRepository.getUser(userId) ?: throw NotFoundUserException
+    override fun getUserDetail(userId: UserId): UserDetail? {
+        val userInfo = userRepository.getUser(userId) ?: return null
 
         val authInfo = userRepository.getAuthInfo(userId)
 
diff --git a/core/src/main/kotlin/com/xorker/draw/user/UserUseCase.kt b/core/src/main/kotlin/com/xorker/draw/user/UserUseCase.kt
index dca9ba13..6c244aa7 100644
--- a/core/src/main/kotlin/com/xorker/draw/user/UserUseCase.kt
+++ b/core/src/main/kotlin/com/xorker/draw/user/UserUseCase.kt
@@ -1,7 +1,7 @@
 package com.xorker.draw.user
 
 interface UserUseCase {
-    fun getUserDetail(userId: UserId): UserDetail
+    fun getUserDetail(userId: UserId): UserDetail?
 
     fun updateUser(userId: UserId, nickname: String): User
 }