diff --git a/Sources/XXMessengerClient/Messenger/Functions/MessengerRegisterAuthCallbacks.swift b/Sources/XXMessengerClient/Messenger/Functions/MessengerRegisterAuthCallbacks.swift
index ad184957aae0c17d24a457d77d047506541eb922..3a8b0a5bcb3585ba2b999710a0c572e6e9186a74 100644
--- a/Sources/XXMessengerClient/Messenger/Functions/MessengerRegisterAuthCallbacks.swift
+++ b/Sources/XXMessengerClient/Messenger/Functions/MessengerRegisterAuthCallbacks.swift
@@ -19,6 +19,6 @@ extension MessengerRegisterAuthCallbacks {
 
 extension MessengerRegisterAuthCallbacks {
   public static let unimplemented = MessengerRegisterAuthCallbacks(
-    run: XCTUnimplemented("\(Self.self)")
+    run: XCTUnimplemented("\(Self.self)", placeholder: Cancellable {})
   )
 }