diff --git a/Package.swift b/Package.swift
index 827c92d..8402e52 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 5.7.1
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 // Copyright 2023 Google LLC