diff --git a/SKPhotoBrowser/SKLocalPhoto.swift b/SKPhotoBrowser/SKLocalPhoto.swift
index f7736c0..4eb9bb2 100644
--- a/SKPhotoBrowser/SKLocalPhoto.swift
+++ b/SKPhotoBrowser/SKLocalPhoto.swift
@@ -15,7 +15,7 @@ public class SKLocalPhoto: NSObject, SKPhotoProtocol {
     public var photoURL: String!
     public var shouldCachePhotoURLImage: Bool = false
     public var caption: String!
-    public var index: Int?
+    public var index: Int = 0
     
     override init() {
         super.init()
diff --git a/SKPhotoBrowser/SKPhoto.swift b/SKPhotoBrowser/SKPhoto.swift
index 5acff7c..b8aef3e 100644
--- a/SKPhotoBrowser/SKPhoto.swift
+++ b/SKPhotoBrowser/SKPhoto.swift
@@ -8,10 +8,10 @@
 
 import UIKit
 
-public protocol SKPhotoProtocol: NSObjectProtocol {
+@objc public protocol SKPhotoProtocol: NSObjectProtocol {
     var underlyingImage: UIImage! { get }
     var caption: String! { get }
-    var index: Int? { get set}
+    var index: Int { get set}
     func loadUnderlyingImageAndNotify()
     func checkCache()
 }
@@ -23,7 +23,7 @@ public class SKPhoto: NSObject, SKPhotoProtocol {
     public var photoURL: String!
     public var shouldCachePhotoURLImage: Bool = false
     public var caption: String!
-    public var index: Int?
+    public var index: Int = 0
 
     override init() {
         super.init()