diff --git a/Sources/OpenGraph/Attribute/Body/ObservedAttribute.swift b/Sources/OpenGraph/Attribute/Body/ObservedAttribute.swift
index 489984bd..9ee62ff1 100644
--- a/Sources/OpenGraph/Attribute/Body/ObservedAttribute.swift
+++ b/Sources/OpenGraph/Attribute/Body/ObservedAttribute.swift
@@ -6,7 +6,7 @@
 //  Status: Complete
 
 public protocol ObservedAttribute: _AttributeBody {
-    func destroy()
+    mutating func destroy()
 }
 
 extension ObservedAttribute {