diff --git a/Sources/LayoutConstraintItem.swift b/Sources/LayoutConstraintItem.swift
index a59de6b..9b61d18 100644
--- a/Sources/LayoutConstraintItem.swift
+++ b/Sources/LayoutConstraintItem.swift
@@ -28,7 +28,7 @@
 #endif
 
 
-public protocol LayoutConstraintItem: class {
+public protocol LayoutConstraintItem: AnyObject {
 }
 
 @available(iOS 9.0, OSX 10.11, *)