diff --git a/DemoApp/MockUserDefaultsDemoLib/Package.swift b/DemoApp/MockUserDefaultsDemoLib/Package.swift
index 5aea6be..3fd0c9a 100644
--- a/DemoApp/MockUserDefaultsDemoLib/Package.swift
+++ b/DemoApp/MockUserDefaultsDemoLib/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.5
+// swift-tools-version:5.6
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
     name: "MockUserDefaultsDemoLib",
     defaultLocalization: "ja",
-    platforms: [.macOS(.v11), .iOS(.v15)],
+    platforms: [.macOS(.v12), .iOS(.v15), .tvOS(.v15), .watchOS(.v8)],
     products: [
         .library(
             name: "MockUserDefaultsDemoLib",
diff --git a/Package.swift b/Package.swift
index 342f058..cdcdbbc 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.5
+// swift-tools-version:5.6
 import PackageDescription
 
 let package = Package(