diff --git a/src/main/java/com/back/web7_9_codecrete_be/domain/auth/controller/AuthController.java b/src/main/java/com/back/web7_9_codecrete_be/domain/auth/controller/AuthController.java
index c7f40e15..d3ccb85f 100644
--- a/src/main/java/com/back/web7_9_codecrete_be/domain/auth/controller/AuthController.java
+++ b/src/main/java/com/back/web7_9_codecrete_be/domain/auth/controller/AuthController.java
@@ -65,8 +65,8 @@ public RsData<?> verifyEmailCode(@Valid @RequestBody EmailVerifyRequest req) {
     @Operation(summary = "닉네임 중복 체크", description = "닉네임이 사용 가능한지 확인합니다.")
     @GetMapping("/nickname/check")
     public RsData<?> checkNickname(@RequestParam String nickname) {
-        boolean available = authService.isNicknameAvailable(nickname);
-        return RsData.success("닉네임 사용 가능 여부 확인", available);
+        authService.isNicknameAvailable(nickname);
+        return RsData.success("사용 가능한 닉네임입니다.");
     }
 
     @Operation(summary = "임시 비밀번호 재발급", description = "특정 이메일로 임시 비밀번호를 발송합니다.")
diff --git a/src/main/java/com/back/web7_9_codecrete_be/domain/auth/service/AuthService.java b/src/main/java/com/back/web7_9_codecrete_be/domain/auth/service/AuthService.java
index 30013ccc..11e89374 100644
--- a/src/main/java/com/back/web7_9_codecrete_be/domain/auth/service/AuthService.java
+++ b/src/main/java/com/back/web7_9_codecrete_be/domain/auth/service/AuthService.java
@@ -85,8 +85,10 @@ public void verifyEmailCode(String email, String code) {
     }
 
     // 닉네임 중복 체크
-    public boolean isNicknameAvailable(String nickname) {
-        return !userRepository.existsByNickname(nickname);
+    public void isNicknameAvailable(String nickname) {
+        if (userRepository.existsByNickname(nickname)) {
+            throw new BusinessException(UserErrorCode.NICKNAME_DUPLICATED);
+        }
     }
 
     // 임시 비밀번호 재발급