diff --git a/umbba-api/src/main/java/sopt/org/umbba/api/service/user/AuthService.java b/umbba-api/src/main/java/sopt/org/umbba/api/service/user/AuthService.java
index cd3923f8..e72c3164 100644
--- a/umbba-api/src/main/java/sopt/org/umbba/api/service/user/AuthService.java
+++ b/umbba-api/src/main/java/sopt/org/umbba/api/service/user/AuthService.java
@@ -131,8 +131,12 @@ private User getUserById(Long userId) {
     }
 
     private User getUserBySocialAndSocialId(SocialPlatform socialPlatform, String socialId) {
-        return userRepository.findBySocialPlatformAndSocialId(socialPlatform, socialId)
-                .orElseThrow(() -> new CustomException(ErrorType.INVALID_USER));
+        List<User> users = userRepository.findBySocialPlatformAndSocialId(socialPlatform, socialId);
+        if (users.isEmpty()) {
+            throw new CustomException(ErrorType.INVALID_USER);
+        }
+
+        return users.get(0);
     }
 
     private boolean isUserBySocialAndSocialId(SocialPlatform socialPlatform, String socialId) {
diff --git a/umbba-domain/src/main/java/sopt/org/umbba/domain/domain/user/repository/UserRepository.java b/umbba-domain/src/main/java/sopt/org/umbba/domain/domain/user/repository/UserRepository.java
index 5e717518..c4935cc2 100644
--- a/umbba-domain/src/main/java/sopt/org/umbba/domain/domain/user/repository/UserRepository.java
+++ b/umbba-domain/src/main/java/sopt/org/umbba/domain/domain/user/repository/UserRepository.java
@@ -16,7 +16,7 @@ public interface UserRepository extends Repository<User, Long> {
     // READ
     Optional<User> findById(Long id);
     boolean existsBySocialPlatformAndSocialId(SocialPlatform socialPlatform, String socialId);
-    Optional<User> findBySocialPlatformAndSocialId(SocialPlatform socialPlatform, String socialId);
+    List<User> findBySocialPlatformAndSocialId(SocialPlatform socialPlatform, String socialId);
     Optional<User> findByFcmToken(String fcmToken);
 
     // DELETE