diff --git a/keyBoard/AppDelegate.m b/keyBoard/AppDelegate.m
index 471d3d5..be66216 100644
--- a/keyBoard/AppDelegate.m
+++ b/keyBoard/AppDelegate.m
@@ -12,7 +12,10 @@
 #import "BaseTabBarController.h"
 #import "LoginViewController.h"
 
-static NSString * const kKBKeyboardExtensionBundleId = @"com.keyBoard.CustomKeyboard";
+// 注意：用于判断系统已启用本输入法扩展的 bundle id 需与扩展 target 的
+// PRODUCT_BUNDLE_IDENTIFIER 完全一致。
+// 当前工程的 CustomKeyboard target 为 com.keyBoardst.CustomKeyboard
+static NSString * const kKBKeyboardExtensionBundleId = @"com.keyBoardst.CustomKeyboard";
 
 @implementation AppDelegate