diff --git a/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionCtl_HandleEvent.swift b/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionCtl_HandleEvent.swift
index 491c3f8f..497468b5 100644
--- a/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionCtl_HandleEvent.swift
+++ b/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionCtl_HandleEvent.swift
@@ -11,6 +11,7 @@ import IMKUtils
 import InputMethodKit
 import NotifierUI
 import Shared
+import SwiftyCapsLockToggler
 
 // MARK: - Facade
 
@@ -183,10 +184,15 @@ public extension SessionCtl {
   /// 切換英數模式開關。
   private func toggleAlphanumericalMode() {
     let status = "NotificationSwitchRevolver".localized
+    let oldValue = isASCIIMode
+    let newValue = isASCIIMode.toggled()
     Notifier.notify(
-      message: isASCIIMode.toggled()
+      message: newValue
         ? NSLocalizedString("Alphanumerical Input Mode", comment: "") + "\n" + status
         : NSLocalizedString("Chinese Input Mode", comment: "") + "\n" + status
     )
+    if oldValue, !newValue, Self.isCapsLocked {
+      CapsLockToggler.turnOff()
+    }
   }
 }