diff --git a/.github/workflows/testflight-build.yml b/.github/workflows/testflight-build.yml
index 898cd17c..71d57c16 100644
--- a/.github/workflows/testflight-build.yml
+++ b/.github/workflows/testflight-build.yml
@@ -62,6 +62,22 @@ jobs:
         with:
           xcode-version: latest-stable
 
+      - name: Resolve Xcode cache key
+        id: xcode-cache
+        if: ${{ !inputs.dry_run }}
+        shell: bash
+        run: |
+          set -euo pipefail
+          xcode_key="$(xcodebuild -version | tr '\n' '-' | sed -E 's/[^A-Za-z0-9._-]+/-/g; s/-$//')"
+          echo "version=$xcode_key" >> "$GITHUB_OUTPUT"
+
+      - name: Restore Swift package cache
+        if: ${{ !inputs.dry_run }}
+        uses: actions/cache/restore@v4
+        with:
+          path: ${{ vars.IOS_WORKDIR || 'ios' }}/SourcePackages
+          key: spm-${{ runner.os }}-${{ runner.arch }}-${{ steps.xcode-cache.outputs.version }}-${{ hashFiles('ios/epac.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
+
       - name: Set up Ruby and Bundler
         if: ${{ !inputs.dry_run }}
         uses: ruby/setup-ruby@v1
@@ -159,6 +175,7 @@ jobs:
           NEW_VERSION: ${{ github.event_name == 'workflow_dispatch' && inputs.version_override || steps.version.outputs.next_version }}
           KEYCHAIN_PASSWORD: ${{ secrets.KEYCHAIN_PASSWORD }}
           APPLE_TEAM_ID: ${{ vars.APPLE_TEAM_ID }}
+          SPM_CLONED_SOURCE_PACKAGES_PATH: SourcePackages
         run: |
           bundle exec fastlane deploy \
             scheme:${{ vars.SCHEME }} \
diff --git a/.github/workflows/warm-spm-cache.yml b/.github/workflows/warm-spm-cache.yml
new file mode 100644
index 00000000..009ef599
--- /dev/null
+++ b/.github/workflows/warm-spm-cache.yml
@@ -0,0 +1,71 @@
+name: Warm Swift Package Cache
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+    paths:
+      - 'ios/epac.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved'
+      - '.github/workflows/warm-spm-cache.yml'
+
+permissions:
+  contents: read
+
+concurrency:
+  group: warm-spm-cache
+  cancel-in-progress: true
+
+jobs:
+  warm:
+    name: Warm Swift package cache
+    runs-on: macos-15
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Select Xcode
+        uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: latest-stable
+
+      - name: Resolve Xcode cache key
+        id: xcode-cache
+        shell: bash
+        run: |
+          set -euo pipefail
+          xcode_key="$(xcodebuild -version | tr '\n' '-' | sed -E 's/[^A-Za-z0-9._-]+/-/g; s/-$//')"
+          echo "version=$xcode_key" >> "$GITHUB_OUTPUT"
+
+      - name: Restore Swift package cache
+        id: spm-cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ios/SourcePackages
+          key: spm-${{ runner.os }}-${{ runner.arch }}-${{ steps.xcode-cache.outputs.version }}-${{ hashFiles('ios/epac.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
+
+      - name: Resolve Swift packages
+        if: ${{ steps.spm-cache.outputs.cache-hit != 'true' }}
+        run: |
+          xcodebuild -resolvePackageDependencies \
+            -project ios/epac.xcodeproj \
+            -scheme epac \
+            -configuration Release \
+            -clonedSourcePackagesDirPath ios/SourcePackages
+
+      - name: Save Swift package cache
+        if: ${{ steps.spm-cache.outputs.cache-hit != 'true' }}
+        uses: actions/cache/save@v4
+        with:
+          path: ios/SourcePackages
+          key: spm-${{ runner.os }}-${{ runner.arch }}-${{ steps.xcode-cache.outputs.version }}-${{ hashFiles('ios/epac.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
+
+      - name: Summary
+        run: |
+          {
+            echo "## Swift package cache"
+            echo ""
+            echo "- Xcode key: ${{ steps.xcode-cache.outputs.version }}"
+            echo "- Cache hit: ${{ steps.spm-cache.outputs.cache-hit || 'false' }}"
+            echo "- Path: ios/SourcePackages"
+          } >> "$GITHUB_STEP_SUMMARY"
diff --git a/ios/fastlane/Fastfile b/ios/fastlane/Fastfile
index d0a2d432..87d2fbaf 100644
--- a/ios/fastlane/Fastfile
+++ b/ios/fastlane/Fastfile
@@ -148,6 +148,7 @@ platform :ios do
       configuration:    "Release",
       export_method:    "app-store",
       xcargs:           extra_xcargs,
+      cloned_source_packages_path: ENV["SPM_CLONED_SOURCE_PACKAGES_PATH"],
       output_directory: "build",
       output_name:      "epac.ipa",
       clean:            false