diff --git a/src/doctor.ts b/src/doctor.ts
index 3b6daee..7715b42 100644
--- a/src/doctor.ts
+++ b/src/doctor.ts
@@ -1,5 +1,4 @@
-import * as _ts from 'typescript'
-import * as fs from 'fs'
+import type _ts from 'typescript'
 import * as path from 'path'
 import { createHost, createService } from './langSvc'
 import { Reporter } from './reporter'
@@ -36,9 +35,9 @@ export class Doctor {
 
     /**
      * Note:
-     * 
+     *
      * since we use CDN-hosted TS runtime, which is a bundled version,
-     * we need to manually added lib.*.d.ts. 
+     * we need to manually added lib.*.d.ts.
      */
     const fileNames = [
       ...parsed.fileNames,
diff --git a/src/langSvc/createHost.ts b/src/langSvc/createHost.ts
index c9e622b..829ce20 100644
--- a/src/langSvc/createHost.ts
+++ b/src/langSvc/createHost.ts
@@ -1,4 +1,4 @@
-import * as _ts from 'typescript'
+import type _ts from 'typescript'
 import * as fs from 'fs'
 import * as path from 'path'
 import { FileEntry } from '../types'
diff --git a/src/langSvc/createService.ts b/src/langSvc/createService.ts
index 2518a35..4186017 100644
--- a/src/langSvc/createService.ts
+++ b/src/langSvc/createService.ts
@@ -1,4 +1,4 @@
-import * as _ts from 'typescript'
+import type _ts from 'typescript'
 
 export const createService = (host: _ts.LanguageServiceHost, ts: typeof _ts) => {
   return ts.createLanguageService(host, ts.createDocumentRegistry())
diff --git a/src/reporter/helper.ts b/src/reporter/helper.ts
index 950af4e..5c5ed77 100644
--- a/src/reporter/helper.ts
+++ b/src/reporter/helper.ts
@@ -1,4 +1,4 @@
-import * as _ts from 'typescript'
+import type _ts from 'typescript'
 import { Message } from '../types'
 import { pos2location } from '../utils'
 
diff --git a/src/reporter/index.ts b/src/reporter/index.ts
index 4851158..390fd1d 100644
--- a/src/reporter/index.ts
+++ b/src/reporter/index.ts
@@ -1,4 +1,4 @@
-import * as _ts from 'typescript'
+import type _ts from 'typescript'
 import { issueCommand } from '@actions/core/lib/command'
 import { nonNullable } from '../utils'
 import { diagnostic2message } from './helper'