diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
index 34042167..1648b1b8 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
@@ -7,7 +7,7 @@
 // requirements defined in MIT License.
 
 import AVFoundation
-import AppKit
+import Cocoa
 
 extension NSSound {
   public static func buzz(fart: Bool = false) {