diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
index b5af85df..c65fc572 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
@@ -47,6 +47,7 @@ public protocol PrefMgrProtocol {
   var onlyLoadFactoryLangModelsIfNeeded: Bool { get set }
   var useIMKCandidateWindow: Bool { get set }
   var enableSwiftUIForTDKCandidates: Bool { get set }
+  var enableMouseScrollingForTDKCandidatesCocoa: Bool { get set }
   var disableSegmentedThickUnderlineInMarkingModeForManagedClients: Bool { get set }
   var maxCandidateLength: Int { get set }
   var shouldNotFartInLieuOfBeep: Bool { get set }
diff --git a/Packages/vChewing_Shared/Sources/Shared/Shared.swift b/Packages/vChewing_Shared/Sources/Shared/Shared.swift
index c348d990..c9bb30ed 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Shared.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Shared.swift
@@ -75,6 +75,7 @@ public enum UserDef: String, CaseIterable {
 
   case kUseIMKCandidateWindow = "UseIMKCandidateWindow"
   case kEnableSwiftUIForTDKCandidates = "EnableSwiftUIForTDKCandidates"
+  case kEnableMouseScrollingForTDKCandidatesCocoa = "EnableMouseScrollingForTDKCandidatesCocoa"
   case kDisableSegmentedThickUnderlineInMarkingModeForManagedClients
     = "DisableSegmentedThickUnderlineInMarkingModeForManagedClients"
 
diff --git a/Source/Modules/PrefMgr_Core.swift b/Source/Modules/PrefMgr_Core.swift
index 7af15400..bcffefd0 100644
--- a/Source/Modules/PrefMgr_Core.swift
+++ b/Source/Modules/PrefMgr_Core.swift
@@ -188,6 +188,9 @@ public class PrefMgr: PrefMgrProtocol {
   @AppProperty(key: UserDef.kEnableSwiftUIForTDKCandidates.rawValue, defaultValue: false)
   public var enableSwiftUIForTDKCandidates: Bool
 
+  @AppProperty(key: UserDef.kEnableMouseScrollingForTDKCandidatesCocoa.rawValue, defaultValue: false)
+  public var enableMouseScrollingForTDKCandidatesCocoa: Bool
+
   @AppProperty(
     key: UserDef.kDisableSegmentedThickUnderlineInMarkingModeForManagedClients.rawValue,
     defaultValue: false