diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
index 50811888..4bb703a1 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/PrefMgrProtocol.swift
@@ -68,6 +68,7 @@ public protocol PrefMgrProtocol {
   var currencyNumeralsEnabled: Bool { get set }
   var halfWidthPunctuationEnabled: Bool { get set }
   var escToCleanInputBuffer: Bool { get set }
+  var acceptLeadingIntonations: Bool { get set }
   var specifyIntonationKeyBehavior: Int { get set }
   var specifyShiftBackSpaceKeyBehavior: Int { get set }
   var specifyShiftTabKeyBehavior: Bool { get set }
diff --git a/Packages/vChewing_Shared/Sources/Shared/Shared.swift b/Packages/vChewing_Shared/Sources/Shared/Shared.swift
index a67e098a..598aa040 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Shared.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Shared.swift
@@ -41,6 +41,7 @@ public enum UserDef: String, CaseIterable {
   case kHalfWidthPunctuationEnabled = "HalfWidthPunctuationEnable"
   case kMoveCursorAfterSelectingCandidate = "MoveCursorAfterSelectingCandidate"
   case kEscToCleanInputBuffer = "EscToCleanInputBuffer"
+  case kAcceptLeadingIntonations = "AcceptLeadingIntonations"
   case kSpecifyIntonationKeyBehavior = "SpecifyIntonationKeyBehavior"
   case kSpecifyShiftBackSpaceKeyBehavior = "SpecifyShiftBackSpaceKeyBehavior"
   case kSpecifyShiftTabKeyBehavior = "SpecifyShiftTabKeyBehavior"
diff --git a/Source/Modules/PrefMgr_Core.swift b/Source/Modules/PrefMgr_Core.swift
index 4c516b1f..3b469af6 100644
--- a/Source/Modules/PrefMgr_Core.swift
+++ b/Source/Modules/PrefMgr_Core.swift
@@ -273,6 +273,9 @@ public class PrefMgr: PrefMgrProtocol {
   @AppProperty(key: UserDef.kEscToCleanInputBuffer.rawValue, defaultValue: true)
   public var escToCleanInputBuffer: Bool
 
+  @AppProperty(key: UserDef.kAcceptLeadingIntonations.rawValue, defaultValue: true)
+  public var acceptLeadingIntonations: Bool
+
   @AppProperty(key: UserDef.kSpecifyIntonationKeyBehavior.rawValue, defaultValue: 0)
   public var specifyIntonationKeyBehavior: Int