diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
index 9464f660..5884b331 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
@@ -74,7 +74,7 @@ public class CtlCandidateTDK: CtlCandidate {
     let panel = NSPanel(
       contentRect: contentRect, styleMask: styleMask, backing: .buffered, defer: false
     )
-    panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel) + 2)
+    panel.level = NSWindow.Level(Int(max(CGShieldingWindowLevel(), kCGPopUpMenuWindowLevel)) + 2)
     panel.hasShadow = true
     panel.isOpaque = false
     panel.backgroundColor = NSColor.clear
diff --git a/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift b/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
index 2e623d58..96352b71 100644
--- a/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
+++ b/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
@@ -97,7 +97,7 @@ public class Notifier: NSWindowController {
     )
     theWindow.contentView = transparentVisualEffect
     theWindow.isMovableByWindowBackground = true
-    theWindow.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel))
+    theWindow.level = NSWindow.Level(Int(max(CGShieldingWindowLevel(), kCGPopUpMenuWindowLevel)))
     theWindow.hasShadow = true
     theWindow.backgroundColor = .textBackgroundColor
     theWindow.title = ""
diff --git a/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift b/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
index 0cb5fb85..eff04bb9 100644
--- a/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
+++ b/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
@@ -32,7 +32,7 @@ public class PopupCompositionBuffer: NSWindowController {
     let panel = NSPanel(
       contentRect: contentRect, styleMask: styleMask, backing: .buffered, defer: false
     )
-    panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel) + 1)
+    panel.level = NSWindow.Level(Int(max(CGShieldingWindowLevel(), kCGPopUpMenuWindowLevel)) + 1)
     panel.hasShadow = true
     panel.backgroundColor = NSColor.controlBackgroundColor
     panel.styleMask = .fullSizeContentView
diff --git a/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift b/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
index 54cee25b..f4ef26c5 100644
--- a/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
+++ b/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
@@ -34,7 +34,7 @@ public class TooltipUI: NSWindowController {
     let panel = NSPanel(
       contentRect: contentRect, styleMask: styleMask, backing: .buffered, defer: false
     )
-    panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel) + 2)
+    panel.level = NSWindow.Level(Int(max(CGShieldingWindowLevel(), kCGPopUpMenuWindowLevel)) + 2)
     panel.hasShadow = true
     panel.backgroundColor = NSColor.controlBackgroundColor
     panel.isMovable = false
diff --git a/Source/Modules/SessionCtl_HandleDisplay.swift b/Source/Modules/SessionCtl_HandleDisplay.swift
index cb769798..6f266226 100644
--- a/Source/Modules/SessionCtl_HandleDisplay.swift
+++ b/Source/Modules/SessionCtl_HandleDisplay.swift
@@ -73,7 +73,7 @@ extension SessionCtl {
   }
 
   public func showCandidates() {
-    guard let client = client() else { return }
+    guard client() != nil else { return }
     updateVerticalTypingStatus()
     isVerticalCandidateWindow = (isVerticalTyping || !PrefMgr.shared.useHorizontalCandidateList)
 
@@ -127,9 +127,7 @@ extension SessionCtl {
     if #available(macOS 10.14, *) {
       // Spotlight 視窗會擋住 IMK 選字窗，所以需要特殊處理。
       if let ctlCandidateCurrent = candidateUI as? CtlCandidateIMK {
-        while ctlCandidateCurrent.windowLevel() <= client.windowLevel() {
-          ctlCandidateCurrent.setWindowLevel(UInt64(max(0, client.windowLevel() + 1000)))
-        }
+        ctlCandidateCurrent.setWindowLevel(UInt64(CGShieldingWindowLevel() + 2))
       }
     }