src/main/kotlin/kr/co/vividnext/sodalive/jwt/TokenProvider.kt

@@ -70,7 +70,7 @@ class TokenProvider(
 
             val memberTokenSet = memberToken.tokenList.toMutableSet()
             memberTokenSet.add(token)
-            memberToken.tokenList = memberTokenSet.toList()
+            memberToken.tokenList = memberTokenSet.toMutableList()
             tokenRepository.save(memberToken)
         }
 

src/main/kotlin/kr/co/vividnext/sodalive/member/token/MemberToken.kt

@@ -7,5 +7,5 @@ import org.springframework.data.redis.core.RedisHash
 data class MemberToken(
     @Id
     val id: Long,
-    var tokenList: List<String>
+    var tokenList: MutableList<String>
 )