diff --git a/__tests__/usecase/createRegisteredCourses.test.ts b/__tests__/usecase/createRegisteredCourses.test.ts
index 3e1265b..0a7be89 100644
--- a/__tests__/usecase/createRegisteredCourses.test.ts
+++ b/__tests__/usecase/createRegisteredCourses.test.ts
@@ -7,7 +7,7 @@ import { AlreadyExistError, InvalidArgumentError } from '../../src/error'
 import { createRegisteredCoursesUseCase } from '../../src/usecase/createRegisteredCourses'
 import { clearDB } from '../database/_cleardb'
 import { deepContaining } from '../_deepContaining'
-import { getConnection, getRepository } from 'typeorm'
+import { getConnection } from 'typeorm'
 import { Tag } from '../../src/database/model/tag'
 
 const userId = v4()
diff --git a/__tests__/usecase/deleteRegisteredCourses.test.ts b/__tests__/usecase/deleteRegisteredCourses.test.ts
index c1caa8b..81f52f6 100644
--- a/__tests__/usecase/deleteRegisteredCourses.test.ts
+++ b/__tests__/usecase/deleteRegisteredCourses.test.ts
@@ -1,15 +1,12 @@
-import clone from 'clone'
 import { getConnection } from 'typeorm'
 import { v4 } from 'uuid'
 import { connectDatabase, disconnectDatabase } from '../../src/database'
 import { RegisteredCourse } from '../../src/database/model/registeredCourse'
 import { Tag } from '../../src/database/model/tag'
 import { CourseMethod, Day, Module } from '../../src/database/type'
-import { InvalidArgumentError, NotFoundError } from '../../src/error'
+import { NotFoundError } from '../../src/error'
 import { deleteRegisteredCoursesUseCase } from '../../src/usecase/deleteRegisteredCourses'
-import { updateRegisteredCourseUseCase } from '../../src/usecase/updateRegisteredCourses'
 import { clearDB } from '../database/_cleardb'
-import { deepContaining } from '../_deepContaining'
 
 const userId = v4()
 const tags = [
diff --git a/__tests__/usecase/getRegisteredCourses.test.ts b/__tests__/usecase/getRegisteredCourses.test.ts
index fbc374c..0df6f95 100644
--- a/__tests__/usecase/getRegisteredCourses.test.ts
+++ b/__tests__/usecase/getRegisteredCourses.test.ts
@@ -1,13 +1,10 @@
-import clone from 'clone'
 import { getConnection } from 'typeorm'
 import { v4 } from 'uuid'
 import { connectDatabase, disconnectDatabase } from '../../src/database'
 import { RegisteredCourse } from '../../src/database/model/registeredCourse'
 import { Tag } from '../../src/database/model/tag'
 import { CourseMethod, Day, Module } from '../../src/database/type'
-import { InvalidArgumentError, NotFoundError } from '../../src/error'
 import { getRegisteredCoursesUseCase } from '../../src/usecase/getRegisteredCourses'
-import { updateRegisteredCourseUseCase } from '../../src/usecase/updateRegisteredCourses'
 import { clearDB } from '../database/_cleardb'
 import { deepContaining } from '../_deepContaining'
 
diff --git a/src/grpc/converter.ts b/src/grpc/converter.ts
index c50df7f..9c1df01 100644
--- a/src/grpc/converter.ts
+++ b/src/grpc/converter.ts
@@ -5,7 +5,6 @@
 import { Metadata, StatusObject } from '@grpc/grpc-js'
 import { Status } from '@grpc/grpc-js/build/src/constants'
 import { ServerErrorResponse } from '@grpc/grpc-js/build/src/server-call'
-import { v4 } from 'uuid'
 import {
   ICourseSchedule,
   IRegisteredCourse,