diff --git a/lib/types.ts b/lib/types.ts
index d334b37..8c6790d 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -1,6 +1,6 @@
-import { ErrorObject } from 'serialize-error'
-import { EventEmitter } from 'events'
-import { Readable } from 'stream'
+import type { ErrorObject } from 'serialize-error'
+import type { EventEmitter } from 'events'
+import type { Readable } from 'stream'
 
 export enum msgType {
   REQUEST = 0,