diff --git a/hello-swift-java/hashing-lib/Package.swift b/hello-swift-java/hashing-lib/Package.swift
index 1b21050..0295118 100644
--- a/hello-swift-java/hashing-lib/Package.swift
+++ b/hello-swift-java/hashing-lib/Package.swift
@@ -63,6 +63,7 @@ let package = Package(
         .product(name: "SwiftJavaRuntimeSupport", package: "swift-java"),
       ],
       swiftSettings: [
+        .swiftLanguageMode(.v5),
         .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"], .when(platforms: [.macOS, .linux, .windows]))
       ],
       plugins: [