diff --git a/Fixtures/SwiftMigrate/ExistentialAnyWithCommonPluginDependencyMigration/Package.swift b/Fixtures/SwiftMigrate/ExistentialAnyWithCommonPluginDependencyMigration/Package.swift
index 638cb789758..1cc039b9215 100644
--- a/Fixtures/SwiftMigrate/ExistentialAnyWithCommonPluginDependencyMigration/Package.swift
+++ b/Fixtures/SwiftMigrate/ExistentialAnyWithCommonPluginDependencyMigration/Package.swift
@@ -4,6 +4,9 @@ import PackageDescription
 
 let package = Package(
     name: "ExistentialAnyMigration",
+    platforms: [
+        .macOS(.v10_15)
+    ],
     targets: [
         .target(name: "Library", dependencies: ["CommonLibrary"], plugins: [.plugin(name: "Plugin")]),
         .plugin(name: "Plugin", capability: .buildTool, dependencies: ["Tool"]),
diff --git a/Fixtures/SwiftMigrate/ExistentialAnyWithPluginMigration/Package.swift b/Fixtures/SwiftMigrate/ExistentialAnyWithPluginMigration/Package.swift
index 5a689efe60d..0c6a2961f58 100644
--- a/Fixtures/SwiftMigrate/ExistentialAnyWithPluginMigration/Package.swift
+++ b/Fixtures/SwiftMigrate/ExistentialAnyWithPluginMigration/Package.swift
@@ -4,6 +4,9 @@ import PackageDescription
 
 let package = Package(
     name: "ExistentialAnyMigration",
+    platforms: [
+        .macOS(.v10_15)
+    ],
     targets: [
         .target(name: "Library", plugins: [.plugin(name: "Plugin")]),
         .plugin(name: "Plugin", capability: .buildTool, dependencies: ["Tool"]),