diff --git a/.gitignore b/.gitignore
index 4c2ae45..bd3ce41 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 *.swp
 *.swo
 ._*
+/.build
diff --git a/Makefile b/Makefile
index eb2a394..08898f6 100644
--- a/Makefile
+++ b/Makefile
@@ -2,25 +2,15 @@ VERSION = 2
 LIBRARY_PREFIX = pam_watchid
 LIBRARY_NAME = $(LIBRARY_PREFIX).so
 DESTINATION = /usr/local/lib/pam
-TARGET = apple-darwin$(shell uname -r)
+TARGET = apple-macosx10.15
 PAM_FILE_BASE = /etc/pam.d/sudo
 PAM_TEXT = auth sufficient $(LIBRARY_NAME)
 PAM_TID_TEXT = auth       sufficient     pam_tid.so
 
-# Determine if the macOS Sequoia SDK or later is available.
-DEFINES =
-# Due to the different ways in which the CLT and Xcode structure their SDK paths, one of the following will always be an empty string depending on what is configured by xcode-select. 
-CLT_SDK_MAJOR_VER = $(shell xcrun --sdk macosx --show-sdk-path | xargs readlink -f | xargs basename | sed 's/MacOSX//' | cut -d. -f1)
-XCODE_SDK_MAJOR_VER = $(shell xcrun --sdk macosx --show-sdk-path | xargs basename | sed 's/MacOSX//' | cut -d. -f1)
-SDK_REQUIRED_MAJOR_VER = 15
-ifeq "$(SDK_REQUIRED_MAJOR_VER)" "$(word 1, $(sort $(SDK_REQUIRED_MAJOR_VER) $(XCODE_SDK_MAJOR_VER) $(CLT_SDK_MAJOR_VER)))"
-	DEFINES += -DSEQUOIASDK
-endif
-
 all:
-	swiftc watchid-pam-extension.swift $(DEFINES) -o $(LIBRARY_PREFIX)_x86_64.so -target x86_64-$(TARGET) -emit-library
-	swiftc watchid-pam-extension.swift $(DEFINES) -o $(LIBRARY_PREFIX)_arm64.so -target arm64-$(TARGET) -emit-library
-	lipo -create $(LIBRARY_PREFIX)_arm64.so $(LIBRARY_PREFIX)_x86_64.so -output $(LIBRARY_NAME)
+	swift build -c release --triple x86_64-$(TARGET)
+	swift build -c release --triple arm64-$(TARGET)
+	lipo -create .build/x86_64-apple-macosx/release/libpam-watchid.dylib .build/arm64-apple-macosx/release/libpam-watchid.dylib -output $(LIBRARY_NAME)
 
 install: all
 	sudo mkdir -p $(DESTINATION)
diff --git a/Package.swift b/Package.swift
new file mode 100644
index 0000000..6082f3d
--- /dev/null
+++ b/Package.swift
@@ -0,0 +1,22 @@
+// swift-tools-version:5.1
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "pam-watchid",
+    platforms: [.macOS(.v10_15)],
+    products: [
+        // Products define the executables and libraries a package produces, making them visible to other packages.
+        .library(
+            name: "pam-watchid",
+            type: .dynamic,
+            targets: ["pam-watchid"]),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package, defining a module or a test suite.
+        // Targets can depend on other targets in this package and products from dependencies.
+        .target(
+            name: "pam-watchid"),
+    ]
+)
diff --git a/watchid-pam-extension.swift b/Sources/pam-watchid/pam_watchid.swift
similarity index 99%
rename from watchid-pam-extension.swift
rename to Sources/pam-watchid/pam_watchid.swift
index 2a46d79..1ea730f 100644
--- a/watchid-pam-extension.swift
+++ b/Sources/pam-watchid/pam_watchid.swift
@@ -80,7 +80,7 @@ private func parseArguments(argc: Int, argv: vchar) -> [String: String] {
 
 private extension LAPolicy {
     static var deviceOwnerAuthenticationIgnoringUserID: LAPolicy {
-#if SEQUOIASDK
+#if compiler(>=6.0)
         if #available(macOS 15, *) {
             return .deviceOwnerAuthenticationWithBiometricsOrCompanion
         } else {