diff --git a/README.md b/README.md
index 85e1f37..444a413 100644
--- a/README.md
+++ b/README.md
@@ -44,9 +44,11 @@ enum AppState: State {
 **2. Create validators**: Validators determine state validity and specify the next state. They conform to the `Validator` protocol.
 
 ```swift
-final class AuthenticationValidator {
+final class AuthenticationValidator: Validator {
     let state: AppState = .authentication
     let nextState: AppState = .app
+    var shouldPerformValidation: PassthroughSubject<Void, Never> = .init()
+    
     var isValid: Bool {
         userManager.currentUser != nil
     }
diff --git a/Sources/StateKit/Validator/Validator.swift b/Sources/StateKit/Validator/Validator.swift
index 377124d..ae96684 100644
--- a/Sources/StateKit/Validator/Validator.swift
+++ b/Sources/StateKit/Validator/Validator.swift
@@ -6,7 +6,7 @@
 //
 
 import Foundation
-import Combine
+@_exported import Combine
 
 public protocol Validator {
     associatedtype _State: State