diff --git a/user-service/src/main/java/kr/mafoo/user/service/MemberService.java b/user-service/src/main/java/kr/mafoo/user/service/MemberService.java
index a9c63e0e..f39dd1c4 100644
--- a/user-service/src/main/java/kr/mafoo/user/service/MemberService.java
+++ b/user-service/src/main/java/kr/mafoo/user/service/MemberService.java
@@ -52,14 +52,20 @@ public Mono<MemberEntity> createNewMember(String username, String profileImageUr
         MemberEntity memberEntity = MemberEntity.newMember(IdGenerator.generate(), username, profileImageUrl, true);
 
         return memberRepository.save(memberEntity)
-            .flatMap(savedMember -> slackService.sendNewMemberNotification(
-                savedMember.getSerialNumber(),
-                savedMember.getId(),
-                savedMember.getName(),
-                savedMember.getProfileImageUrl(),
-                savedMember.getCreatedAt().toString(),
-                userAgent
-            ).then(Mono.just(savedMember)));
+            .flatMap(savedMember ->
+                memberRepository.findById(savedMember.getId())
+                    .flatMap(fetchedMember ->
+                        slackService.sendNewMemberNotification(
+                            fetchedMember.getSerialNumber(),
+                            fetchedMember.getId(),
+                            fetchedMember.getName(),
+                            fetchedMember.getProfileImageUrl(),
+                            fetchedMember.getCreatedAt().toString(),
+                            userAgent
+                        )
+                    )
+                    .then(Mono.just(savedMember))
+            );
     }
 
     @Transactional