diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
index 6391891e..5fadb50c 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
@@ -14,6 +14,7 @@ public protocol CtlCandidateDelegate {
   func candidatePairHighlightChanged(at index: Int)
   func candidatePairRightClicked(at index: Int, action: CandidateContextMenuAction)
   func candidates(_ sender: Any!) -> [Any]!
+  func deductCandidateIndex(from candidateString: String) -> Int
   func resetCandidateWindowOrigin()
   @discardableResult func reverseLookup(for value: String) -> [String]
   var selectionKeys: String { get }
diff --git a/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift b/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
index a0671030..063f47c9 100644
--- a/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
+++ b/Source/Modules/UIModules/CandidateUI/IMKCandidatesImpl.swift
@@ -148,7 +148,11 @@ public class CtlCandidateIMK: IMKCandidates, CtlCandidateProtocol {
   public func candidateIndexAtKeyLabelIndex(_: Int) -> Int? { 0 }
 
   public var highlightedIndex: Int {
-    get { selectedCandidate() }
+    get {
+      let returned = selectedCandidate()
+      guard let strCurrentCandidate = selectedCandidateString() else { return returned }
+      return delegate?.deductCandidateIndex(from: strCurrentCandidate.string) ?? returned
+    }
     set { selectCandidate(withIdentifier: newValue) }
   }
 }