diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..b51a116
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,40 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - "**"
+  schedule:
+    - cron: '3 3 * * 2'  # 3:03 AM, every Tuesday
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  macOS:
+    name: ${{ matrix.platform }} (Swift ${{ matrix.swift }})
+    runs-on: macos-13
+    strategy:
+      fail-fast: false
+      matrix:
+        platform:
+          - iOS
+          - macOS
+          - tvOS
+          - watchOS
+        swift:
+          - 5.8
+          - 5.9
+    steps:
+      - name: Git Checkout
+        uses: actions/checkout@v4
+
+      - name: Test Library
+        uses: mxcl/xcodebuild@v2
+        with:
+          platform: ${{ matrix.platform }}
+          action: test
diff --git a/Package.swift b/Package.swift
index 9c18a35..90c008b 100644
--- a/Package.swift
+++ b/Package.swift
@@ -5,7 +5,12 @@ import PackageDescription
 
 let package = Package(
   name: "Republished",
-  platforms: [.iOS(.v15), .macOS(.v13)],
+  platforms: [
+    .iOS(.v13),
+    .macOS(.v10_15),
+    .tvOS(.v13),
+    .watchOS(.v6),
+  ],
   products: [
     .library(
       name: "Republished",
diff --git a/RepublishedExampleApp/RepublishedExampleApp.xcodeproj/project.pbxproj b/RepublishedExampleApp/RepublishedExampleApp.xcodeproj/project.pbxproj
index 2900460..f1f4b29 100644
--- a/RepublishedExampleApp/RepublishedExampleApp.xcodeproj/project.pbxproj
+++ b/RepublishedExampleApp/RepublishedExampleApp.xcodeproj/project.pbxproj
@@ -279,7 +279,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -333,7 +333,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;