diff --git a/Sources/SwiftNetwork/Protocols/ProtocolDefinition.swift b/Sources/SwiftNetwork/Protocols/ProtocolDefinition.swift
index 2666414..7c9622e 100644
--- a/Sources/SwiftNetwork/Protocols/ProtocolDefinition.swift
+++ b/Sources/SwiftNetwork/Protocols/ProtocolDefinition.swift
@@ -14,7 +14,7 @@
 
 @_spi(Essentials)
 @available(Network 0.1.0, *)
-public enum ProtocolLevel: Sendable {
+public enum ProtocolLevel: Sendable, Hashable {
     case link
     case internet
     case transport