diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dd86352..e30afc5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,9 +17,9 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - xcode-version: 15.4.0
-            ios-sim: 'platform=iOS Simulator,name=iPhone 15'
-            os: macos-14
+          - xcode-version: 16.4
+            ios-sim: 'platform=iOS Simulator,name=iPhone 16'
+            os: macos-15
 
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/manual-publish-docs.yml b/.github/workflows/manual-publish-docs.yml
index 9b05e93..1a43ce4 100644
--- a/.github/workflows/manual-publish-docs.yml
+++ b/.github/workflows/manual-publish-docs.yml
@@ -4,7 +4,7 @@ on:
 name: Publish Documentation
 jobs:
   build-publish:
-    runs-on: macos-14
+    runs-on: macos-15
 
     permissions:
       id-token: write # Needed if using OIDC to get release secrets.
@@ -16,8 +16,8 @@ jobs:
       - name: Build and Test
         uses: ./.github/actions/ci
         with:
-          xcode-version: 15.4.0
-          ios-sim: 'platform=iOS Simulator,name=iPhone 15'
+          xcode-version: 16.4
+          ios-sim: 'platform=iOS Simulator,name=iPhone 16'
           token: ${{ secrets.GITHUB_TOKEN }}
 
       - uses: ./.github/actions/build-docs
diff --git a/.github/workflows/manual-publish.yml b/.github/workflows/manual-publish.yml
index 08568f5..c660025 100644
--- a/.github/workflows/manual-publish.yml
+++ b/.github/workflows/manual-publish.yml
@@ -9,7 +9,7 @@ on:
 
 jobs:
   build-publish:
-    runs-on: macos-14
+    runs-on: macos-15
 
     # Needed to get tokens during publishing.
     permissions:
@@ -27,8 +27,8 @@ jobs:
 
       - uses: ./.github/actions/ci
         with:
-          xcode-version: 15.4.0
-          ios-sim: 'platform=iOS Simulator,name=iPhone 15'
+          xcode-version: 16.4
+          ios-sim: 'platform=iOS Simulator,name=iPhone 16'
           token: ${{ secrets.GITHUB_TOKEN }}
 
       - uses: ./.github/actions/publish
diff --git a/.github/workflows/release-please.yml b/.github/workflows/release-please.yml
index b7020ff..6acdcb0 100644
--- a/.github/workflows/release-please.yml
+++ b/.github/workflows/release-please.yml
@@ -7,7 +7,7 @@ on:
 
 jobs:
   release-package:
-    runs-on: macos-14
+    runs-on: macos-15
 
     permissions:
       id-token: write # Needed if using OIDC to get release secrets.
@@ -45,8 +45,8 @@ jobs:
       - uses: ./.github/actions/ci
         if: ${{ steps.release.outputs.releases_created == 'true' }}
         with:
-          xcode-version: 15.4.0
-          ios-sim: 'platform=iOS Simulator,name=iPhone 15'
+          xcode-version: 16.4
+          ios-sim: 'platform=iOS Simulator,name=iPhone 16'
           token: ${{ secrets.GITHUB_TOKEN }}
 
       - uses: ./.github/actions/build-docs