diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
new file mode 100644
index 00000000..9aab23a9
--- /dev/null
+++ b/.github/workflows/build-and-test.yml
@@ -0,0 +1,80 @@
+name: Build and Test (PR)
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+concurrency:
+  group: build-and-test-${{ github.head_ref || github.ref }}
+  cancel-in-progress: true
+
+run-name: Build and Test
+
+jobs:
+  build-and-test:
+    runs-on: macos-14
+
+    env:
+      DESTINATION: 'generic/platform=iOS Simulator'
+      # Connectors to build — Yospace excluded (requires proprietary YOAdManagement SDK)
+      BUILD_SCHEMES: >-
+        THEOplayerConnectorUtilities
+        THEOplayerConnectorConviva
+        THEOplayerConnectorNielsen
+        THEOplayerConnectorSideloadedSubtitle
+        THEOplayerConnectorUplynk
+      # Test schemes to run
+      TEST_SCHEMES: >-
+        THEOplayerConnectorUplynkTests
+
+    steps:
+      - uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: '16.2.0'
+
+      - name: Log environment
+        run: |
+          echo "macOS:" && sw_vers
+          echo "Xcode:" && xcodebuild -version
+          echo "Swift:" && swift --version
+
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Resolve SPM dependencies
+        run: |
+          xcodebuild -resolvePackageDependencies \
+            -scheme THEOplayerConnectorUtilities \
+            -destination "$DESTINATION"
+
+      - name: Build connectors
+        run: |
+          set -euo pipefail
+          for scheme in $BUILD_SCHEMES; do
+            echo "----------------------------------------"
+            echo "Building: $scheme"
+            echo "----------------------------------------"
+            xcodebuild build \
+              -scheme "$scheme" \
+              -destination "$DESTINATION" \
+              -skipPackagePluginValidation \
+              | xcpretty
+          done
+
+      - name: Run tests
+        run: |
+          set -euo pipefail
+          SIM_DEST='platform=iOS Simulator,name=iPhone 16'
+          for scheme in $TEST_SCHEMES; do
+            echo "----------------------------------------"
+            echo "Testing: $scheme"
+            echo "----------------------------------------"
+            xcodebuild test \
+              -scheme "$scheme" \
+              -destination "$SIM_DEST" \
+              -skipPackagePluginValidation \
+              | xcpretty
+          done
diff --git a/Code/Uplynk/Tests/Mocks/MockAdBreak.swift b/Code/Uplynk/Tests/Mocks/MockAdBreak.swift
index 86738737..c4e51bf0 100644
--- a/Code/Uplynk/Tests/Mocks/MockAdBreak.swift
+++ b/Code/Uplynk/Tests/Mocks/MockAdBreak.swift
@@ -20,7 +20,7 @@ struct MockAdBreak: AdBreak {
 
 struct MockAd: Ad {
     let isSlate = false
-    var adBreak: AdBreak = MockAdBreak()
+    var adBreak: AdBreak? = MockAdBreak()
     var companions: [CompanionAd] = []
     var type: String = ""
     var id: String?
diff --git a/Package.swift b/Package.swift
index a13cc93c..a1e5b4a2 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.3
+// swift-tools-version:5.5
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -85,6 +85,13 @@ let package = Package(
                 "THEOplayerConnectorUplynk"
             ],
             path: "Code/Uplynk/Tests"
+        ),
+        .testTarget(
+            name: "THEOplayerConnectorSideloadedSubtitleTests",
+            dependencies: [
+                "THEOplayerConnectorSideloadedSubtitle"
+            ],
+            path: "Code/Sideloaded-TextTracks/Tests/THEOplayerConnectorSideloadedSubtitleTests"
         )
     ]
 )