diff --git a/API-Server/src/main/java/swm/hkcc/LGTM/app/modules/serverDrivenUI/domain/ABTestUserGroupRepository.java b/API-Server/src/main/java/swm/hkcc/LGTM/app/modules/serverDrivenUI/domain/ABTestUserGroupRepository.java
index 41521b23..79e7f2a6 100644
--- a/API-Server/src/main/java/swm/hkcc/LGTM/app/modules/serverDrivenUI/domain/ABTestUserGroupRepository.java
+++ b/API-Server/src/main/java/swm/hkcc/LGTM/app/modules/serverDrivenUI/domain/ABTestUserGroupRepository.java
@@ -7,7 +7,7 @@
 import java.util.Optional;
 
 public interface ABTestUserGroupRepository extends JpaRepository<ABTestUserGroup, Long> {
-    @Cacheable(value = "ab_test_user_group", key = "#p0 +'::'+ #p1")
+    @Cacheable(value = "ab_test_user_group", key = "#p1.concat(':').concat(#p0)")
     @Query("select a.groupName from ABTestUserGroup a where a.memberId = ?1 and a.testName = ?2")
     Optional<String> findGroupNameByMemberIdAndTestName(Long memberId, String testName);