diff --git a/Sources/AsyncImage.swift b/Sources/AsyncImage.swift
index 227ab7e..58d75d2 100644
--- a/Sources/AsyncImage.swift
+++ b/Sources/AsyncImage.swift
@@ -17,24 +17,24 @@ public protocol AsyncImage {
 extension AsyncImage {
     public var isEdited: Bool {
         get {
-            return objc_getAssociatedObject(self, &AsyncImageKeys.isEdited) as? Bool ?? false
+            return objc_getAssociatedObject(self, AsyncImageKeys.isEdited) as? Bool ?? false
         }
         set {
-            objc_setAssociatedObject(self, &AsyncImageKeys.isEdited, newValue, .OBJC_ASSOCIATION_RETAIN)
+            objc_setAssociatedObject(self, AsyncImageKeys.isEdited, newValue, .OBJC_ASSOCIATION_RETAIN)
         }
     }
 
     public var editedImage: UIImage? {
         get {
-            return objc_getAssociatedObject(self, &AsyncImageKeys.editedImage) as? UIImage ?? nil
+            return objc_getAssociatedObject(self, AsyncImageKeys.editedImage) as? UIImage ?? nil
         }
         set {
-            objc_setAssociatedObject(self, &AsyncImageKeys.editedImage, newValue, .OBJC_ASSOCIATION_RETAIN)
+            objc_setAssociatedObject(self, AsyncImageKeys.editedImage, newValue, .OBJC_ASSOCIATION_RETAIN)
         }
     }
 }
 
 private enum AsyncImageKeys {
-    static var isEdited = "isEdited"
-    static var editedImage = "editedImage"
+    static let isEdited = malloc(1)!
+    static let editedImage = malloc(1)!
 }
diff --git a/Sources/Extensions/PHAsset+AsyncImage.swift b/Sources/Extensions/PHAsset+AsyncImage.swift
index dcaf9d7..a74415a 100644
--- a/Sources/Extensions/PHAsset+AsyncImage.swift
+++ b/Sources/Extensions/PHAsset+AsyncImage.swift
@@ -18,10 +18,10 @@ extension PHAsset: AsyncImage {
     */
     public var requests: [PHImageRequestID] {
         get {
-            return objc_getAssociatedObject(self, &Keys.requests) as? [PHImageRequestID] ?? []
+            return objc_getAssociatedObject(self, Keys.requests) as? [PHImageRequestID] ?? []
         }
         set {
-            objc_setAssociatedObject(self, &Keys.requests, newValue, .OBJC_ASSOCIATION_RETAIN)
+            objc_setAssociatedObject(self, Keys.requests, newValue, .OBJC_ASSOCIATION_RETAIN)
         }
     }
 
@@ -72,6 +72,6 @@ extension PHAsset: AsyncImage {
     }
 
     private enum Keys {
-        static var requests = "requests"
+        static let requests = malloc(1)!
     }
 }