diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
index 73f3435a..3876030b 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
@@ -39,7 +39,7 @@ open class CtlCandidate: NSWindowController, CtlCandidateProtocol {
     return result.blended(withFraction: colorBlendAmount, of: blendingAgainstTarget)!
   }
 
-  open weak var delegate: CtlCandidateDelegate? {
+  open var delegate: CtlCandidateDelegate? {
     didSet {
       reloadData()
     }
diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
index 67f5cc3d..1a013e82 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
@@ -8,7 +8,7 @@
 
 import Cocoa
 
-public protocol CtlCandidateDelegate: AnyObject {
+public protocol CtlCandidateDelegate {
   func candidatePairs(conv: Bool) -> [(String, String)]
   func candidatePairSelected(at index: Int)
   func candidates(_ sender: Any!) -> [Any]!
diff --git a/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift b/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
index 73ed646d..d24949a5 100644
--- a/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
+++ b/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
@@ -18,7 +18,7 @@ public class CtlCandidateIMK: IMKCandidates, CtlCandidateProtocol {
   public static let defaultIMKSelectionKey: [UInt16: String] = [
     18: "1", 19: "2", 20: "3", 21: "4", 23: "5", 22: "6", 26: "7", 28: "8", 25: "9",
   ]
-  public weak var delegate: CtlCandidateDelegate? {
+  public var delegate: CtlCandidateDelegate? {
     didSet {
       reloadData()
     }