diff --git a/src/main/java/com/example/onederful/domain/user/repository/UserRepository.java b/src/main/java/com/example/onederful/domain/user/repository/UserRepository.java
index fa642f7..889e6c9 100644
--- a/src/main/java/com/example/onederful/domain/user/repository/UserRepository.java
+++ b/src/main/java/com/example/onederful/domain/user/repository/UserRepository.java
@@ -6,8 +6,7 @@
 import java.util.Optional;
 
 public interface UserRepository extends JpaRepository<User, Long> {
-    boolean existsByEmail(String email);
-    boolean existsByUsername(String username);
+    Optional<User> findByEmail(String email);
     Optional<User> findByUsername(String username);
 
 }
diff --git a/src/main/java/com/example/onederful/domain/user/service/UserService.java b/src/main/java/com/example/onederful/domain/user/service/UserService.java
index 4e1520f..f6c7dcb 100644
--- a/src/main/java/com/example/onederful/domain/user/service/UserService.java
+++ b/src/main/java/com/example/onederful/domain/user/service/UserService.java
@@ -32,15 +32,14 @@ public class UserService {
     public UserResponseDto signup(RequestDto dto){
         
         // 이메일 중복 확인
-        if(userRepository.existsByEmail(dto.getEmail())){
-            throw new CustomException(ErrorCode.DUPLICATE_EMAIL);
-        }
-
+        userRepository.findByEmail(dto.getEmail()).ifPresent(
+                user -> {throw new CustomException(ErrorCode.DUPLICATE_EMAIL);}
+        );
 
         // 아이디 중복 확인
-        if(userRepository.existsByUsername(dto.getUsername())){
-            throw new CustomException(ErrorCode.DUPLICATE_USER);
-        }
+        userRepository.findByUsername(dto.getUsername()).ifPresent(
+                user -> {throw new CustomException(ErrorCode.DUPLICATE_USER);}
+        );
 
         // Dto → Entity
         User user = UserMapper.user(dto);