diff --git a/Package.swift b/Package.swift
index 01b5e95..a7a52f3 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:4.0
+// swift-tools-version:5.4.0
 
 import PackageDescription
 
diff --git a/Sources/JWA/JWA.swift b/Sources/JWA/JWA.swift
index 2e02f7d..89b6155 100644
--- a/Sources/JWA/JWA.swift
+++ b/Sources/JWA/JWA.swift
@@ -3,7 +3,7 @@ import Foundation
 
 /// Represents a JSON Web Algorithm (JWA)
 /// https://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-40
-public protocol Algorithm: class {
+public protocol Algorithm: AnyObject {
   var name: String { get }
 }