diff --git a/.github/workflows/build-pr.yml b/.github/workflows/build-pr.yml
index 0d37793fd3..b8d048d805 100644
--- a/.github/workflows/build-pr.yml
+++ b/.github/workflows/build-pr.yml
@@ -46,7 +46,7 @@ jobs:
       - run: sh -x build.sh verify-osx
 
   osx-16:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx on Xcode 16
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.app/Contents/Developer'
@@ -55,7 +55,7 @@ jobs:
       - run: sh -x build.sh verify-osx
 
   osx-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -64,7 +64,7 @@ jobs:
       - run: sh -x build.sh verify-osx
 
   osx-encryption-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx-encryption on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -82,7 +82,7 @@ jobs:
       - run: sh -x build.sh verify-swiftpm
 
   swiftpm-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test swiftpm on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -109,7 +109,7 @@ jobs:
       - run: sh -x build.sh verify-swiftpm-debug
 
   swiftpm-debug-16:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test swiftpm-debug on Xcode 16
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.app/Contents/Developer'
@@ -118,7 +118,7 @@ jobs:
       - run: sh -x build.sh verify-swiftpm-debug
 
   swiftpm-debug-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test swiftpm-debug on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -127,7 +127,7 @@ jobs:
       - run: sh -x build.sh verify-swiftpm-debug
 
   swiftpm-address-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test swiftpm-address on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -136,7 +136,7 @@ jobs:
       - run: sh -x build.sh verify-swiftpm-address
 
   swiftpm-thread-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test swiftpm-thread on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -154,7 +154,7 @@ jobs:
       - run: sh -x build.sh verify-ios-static
 
   ios-static-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test ios-static on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -172,7 +172,7 @@ jobs:
       - run: sh -x build.sh verify-ios
 
   ios-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test ios on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -190,7 +190,7 @@ jobs:
       - run: sh -x build.sh verify-watchos
 
   watchos-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test watchos on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -208,7 +208,7 @@ jobs:
       - run: sh -x build.sh verify-tvos
 
   tvos-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test tvos on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -226,7 +226,7 @@ jobs:
       - run: sh -x build.sh verify-visionos
 
   visionos-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test visionos on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -253,7 +253,7 @@ jobs:
       - run: sh -x build.sh verify-osx-swift
 
   osx-swift-16:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx-swift on Xcode 16
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.app/Contents/Developer'
@@ -262,7 +262,7 @@ jobs:
       - run: sh -x build.sh verify-osx-swift
 
   osx-swift-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx-swift on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -280,7 +280,7 @@ jobs:
       - run: sh -x build.sh verify-ios-swift
 
   ios-swift-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test ios-swift on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -298,7 +298,7 @@ jobs:
       - run: sh -x build.sh verify-tvos-swift
 
   tvos-swift-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test tvos-swift on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -307,7 +307,7 @@ jobs:
       - run: sh -x build.sh verify-tvos-swift
 
   osx-swift-evolution-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test osx-swift-evolution on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -316,7 +316,7 @@ jobs:
       - run: sh -x build.sh verify-osx-swift-evolution
 
   ios-swift-evolution-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test ios-swift-evolution on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -325,7 +325,7 @@ jobs:
       - run: sh -x build.sh verify-ios-swift-evolution
 
   tvos-swift-evolution-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test tvos-swift-evolution on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -343,7 +343,7 @@ jobs:
       - run: sh -x build.sh verify-catalyst
 
   catalyst-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test catalyst on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -361,7 +361,7 @@ jobs:
       - run: sh -x build.sh verify-catalyst-swift
 
   catalyst-swift-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test catalyst-swift on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -370,7 +370,7 @@ jobs:
       - run: sh -x build.sh verify-catalyst-swift
 
   xcframework-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test xcframework on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -397,7 +397,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-osx
 
   cocoapods-osx-16:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-osx on Xcode 16
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.app/Contents/Developer'
@@ -406,7 +406,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-osx
 
   cocoapods-osx-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-osx on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -415,7 +415,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-osx
 
   cocoapods-ios-static-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-ios-static on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -424,7 +424,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-ios-static
 
   cocoapods-ios-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-ios on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -433,7 +433,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-ios
 
   cocoapods-watchos-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-watchos on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -442,7 +442,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-watchos
 
   cocoapods-tvos-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-tvos on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -451,7 +451,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-tvos
 
   cocoapods-catalyst-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test cocoapods-catalyst on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
@@ -460,7 +460,7 @@ jobs:
       - run: sh -x build.sh verify-cocoapods-catalyst
 
   ios-swiftui-16_1_beta_2:
-    runs-on: macos-14
+    runs-on: macos-15
     name: Test ios-swiftui on Xcode 16.1_beta_2
     env:
       DEVELOPER_DIR: '/Applications/Xcode_16.1_beta_2.app/Contents/Developer'
diff --git a/.github/workflows/master-push.yml b/.github/workflows/master-push.yml
index 1f4a666c78..3bb0d22c47 100644
--- a/.github/workflows/master-push.yml
+++ b/.github/workflows/master-push.yml
@@ -8,8 +8,8 @@ on:
 env:
   XCODE_VERSION: "['15.3', '15.4', '16', '16.1_beta_2']"
   PLATFORM: "['ios', 'osx', 'watchos', 'tvos', 'catalyst', 'visionos']"
-  DOC_VERSION: '15.4'
   RELEASE_VERSION: '15.4'
+  DEVELOPER_DIR: /Applications/Xcode_15.4.app/Contents/Developer
 jobs:
   prepare:
       runs-on: ubuntu-latest
@@ -38,8 +38,6 @@ jobs:
         - uses: ruby/setup-ruby@v1
           with:
             bundler-cache: true
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.DOC_VERSION }}.app
         - name: Prepare docs for packaging
           run: bundle exec sh -x build.sh release-package-docs
         - name: Upload docs to artifacts library
@@ -61,15 +59,22 @@ jobs:
             name: realm-examples
             path: realm-examples.zip
   build-product: # Creates framework for each platform, xcode version, target and configuration
-      runs-on: macos-14
       name: Package framework
       needs: prepare
       strategy:
-        max-parallel: 20 # Blocks of 20, therefore if any of the build fails, we don't get a lot of XCode Clouds builds hanging, which are expensive.
+        max-parallel: 20
         matrix:
           platform: ${{ fromJSON(needs.prepare.outputs.PLATFORM_MATRIX) }}
-          xcode-version: ${{ fromJSON(needs.prepare.outputs.XCODE_VERSIONS_MATRIX) }}
           configuration: [swift, static]
+          include:
+            - xcode-version: 15.3
+              os: macos-14
+            - xcode-version: 15.4
+              os: macos-14
+            - xcode-version: 16
+              os: macos-15
+            - xcode-version: 16.1_beta_2
+              os: macos-15
           exclude:
             - platform: osx
               configuration: static
@@ -81,12 +86,16 @@ jobs:
               configuration: static
             - platform: catalyst
               configuration: static
-            - platform: visionos
-              xcode-version: 15.1
+      runs-on: ${{ matrix.os }}
+      env:
+        DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode-version }}.app/Contents/Developer
       steps:
         - uses: actions/checkout@v4
+        - name: Download visionOS
+          if: matrix.platform == 'visionos' && matrix.os == 'macos-14'
+          run: xcodebuild -downloadPlatform visionOS
         - name: Build ${{ matrix.platform }} with Xcode ${{ matrix.xcode-version }}
-          run: DEVELOPER_DIR=/Applications/Xcode_${{ matrix.xcode-version }}.app/Contents/Developer sh build.sh ${{ matrix.platform }}-${{matrix.configuration}}
+          run: sh build.sh ${{ matrix.platform }}-${{matrix.configuration}}
         - run: rm -r build/DerivedData
         - name: Upload framework
           uses: actions/upload-artifact@v4
@@ -95,27 +104,34 @@ jobs:
             path: build
             compression-level: 1
   package-xcframework-platform: # Creates xcframework for each platform and xcode version
-      runs-on: macos-14
       name: Package xcframework for platform
       needs: [build-product, prepare]
       strategy:
         matrix:
           platform: ${{ fromJSON(needs.prepare.outputs.PLATFORM_MATRIX) }}
-          xcode-version: ${{ fromJSON(needs.prepare.outputs.XCODE_VERSIONS_MATRIX) }}
-          exclude:
-            - platform: visionos
-              xcode-version: 15.1
+          include:
+            - xcode-version: 15.3
+              os: macos-14
+            - xcode-version: 15.4
+              os: macos-14
+            - xcode-version: 16
+              os: macos-15
+            - xcode-version: 16.1_beta_2
+              os: macos-15
+      runs-on: ${{ matrix.os }}
+      env:
+        DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode-version }}.app/Contents/Developer
       steps:
         - uses: actions/checkout@v4
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
         - name: Install the Apple certificate and provisioning profile
           env:
             DEVELOPMENT_CERTIFICATE_BASE64: ${{ secrets.DEVELOPMENT_CERTIFICATE_BASE64 }}
             P12_PASSWORD: ${{ secrets.P12_PASSWORD }}
             KEYCHAIN_PASSWORD: ${{ secrets.KEYCHAIN_PASSWORD }}
-          run: |
-            sh -x build.sh install-apple-certificates
+          run: sh -x build.sh install-apple-certificates
+        - name: Download visionOS
+          if: matrix.platform == 'visionos' && matrix.os == 'macos-14'
+          run: xcodebuild -downloadPlatform visionOS
         - name: Restore frameworks
           uses: actions/download-artifact@v4
           with:
@@ -123,8 +139,7 @@ jobs:
         - name: Create xcframework
           env:
             SIGNING_IDENTITY: ${{ secrets.SIGNING_IDENTITY }}
-          run: |
-            sh -x build.sh release-create-xcframework-${{ matrix.xcode-version }} ${{ matrix.platform }}
+          run: sh -x build.sh release-create-xcframework-${{ matrix.xcode-version }} ${{ matrix.platform }}
         - name: Upload xcframework
           uses: actions/upload-artifact@v4
           with:
@@ -136,15 +151,12 @@ jobs:
       needs: [package-xcframework-platform, prepare]
       steps:
         - uses: actions/checkout@v4
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
         - name: Install the Apple certificate and provisioning profile
           env:
             DEVELOPMENT_CERTIFICATE_BASE64: ${{ secrets.DEVELOPMENT_CERTIFICATE_BASE64 }}
             P12_PASSWORD: ${{ secrets.P12_PASSWORD }}
             KEYCHAIN_PASSWORD: ${{ secrets.KEYCHAIN_PASSWORD }}
-          run: |
-            sh -x build.sh install-apple-certificates
+          run: sh -x build.sh install-apple-certificates
         - name: Restore packages xcframeworks
           uses: actions/download-artifact@v4
           with:
@@ -152,8 +164,7 @@ jobs:
         - name: Create release
           env:
             SIGNING_IDENTITY: ${{ secrets.SIGNING_IDENTITY }}
-          run: |
-            sh -x build.sh release-package
+          run: sh -x build.sh release-package
         - name: Upload release artifactss
           uses: actions/upload-artifact@v4
           with:
@@ -170,8 +181,6 @@ jobs:
       needs: [package-release, prepare]
       steps:
         - uses: actions/checkout@v4
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
         - name: Restore release
           uses: actions/download-artifact@v4
           with:
@@ -184,8 +193,6 @@ jobs:
       needs: package-release
       steps:
         - uses: actions/checkout@v4
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
         - name: Test ios static
           run: sh -x build.sh test-ios-static
   test-osx-static:
@@ -194,8 +201,6 @@ jobs:
       needs: package-release
       steps:
         - uses: actions/checkout@v4
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
         - name: Test osx static
           run: |
             export REALM_DISABLE_METADATA_ENCRYPTION=1
@@ -226,8 +231,9 @@ jobs:
         - uses: ruby/setup-ruby@v1
           with:
             bundler-cache: true
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ env.RELEASE_VERSION }}.app
+        - name: Download visionOS
+          if: matrix.platform == 'visionos' && matrix.os == 'macos-14'
+          run: xcodebuild -downloadPlatform visionOS
         - name: Restore release
           uses: actions/download-artifact@v4
           if: ${{ matrix.installation == 'xcframework' }}
@@ -244,21 +250,28 @@ jobs:
             cd examples/installation
             bundle exec ./build.rb ${{ matrix.platform }} ${{ matrix.installation }} ${{ matrix.linkage }}
   test-installation-xcframework:
-      runs-on: macos-14
       name: Run installation test for xcframework
       needs: [package-release, prepare]
-      env:
-        PLATFORM: 'osx'
       strategy:
         matrix:
-          xcode-version: ${{ fromJSON(needs.prepare.outputs.XCODE_VERSIONS_MATRIX) }}
+          include:
+            - xcode-version: 15.3
+              os: macos-14
+            - xcode-version: 15.4
+              os: macos-14
+            - xcode-version: 16
+              os: macos-15
+            - xcode-version: 16.1_beta_2
+              os: macos-15
+      env:
+        PLATFORM: 'osx'
+        DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode-version }}.app/Contents/Developer
+      runs-on: ${{ matrix.os }}
       steps:
         - uses: actions/checkout@v4
         - uses: ruby/setup-ruby@v1
           with:
             bundler-cache: true
-        - name: Select Xcode Version
-          run: sudo xcode-select -switch /Applications/Xcode_${{ matrix.xcode-version }}.app
         - name: Restore release
           uses: actions/download-artifact@v4
           with:
diff --git a/build.sh b/build.sh
index d4e32654d1..194e2987db 100755
--- a/build.sh
+++ b/build.sh
@@ -310,6 +310,14 @@ plist_get() {
     /usr/libexec/PlistBuddy -c "Print :$2" "$1" 2> /dev/null
 }
 
+iphone_name() {
+    if (( $(xcode_version_major) < 16 )); then
+        echo 'iPhone 14'
+    else
+        echo 'iPhone 16'
+    fi
+}
+
 ######################################
 # Device Test Helper
 ######################################
@@ -519,11 +527,7 @@ case "$COMMAND" in
     "xcframework")
         # Build all of the requested frameworks
         shift
-        if (( $(xcode_version_major) < 15 )); then
-            PLATFORMS="${*:-osx ios watchos tvos catalyst}"
-        else
-            PLATFORMS="${*:-osx ios watchos tvos catalyst visionos}"
-        fi
+        PLATFORMS="${*:-osx ios watchos tvos catalyst visionos}"
         for platform in $PLATFORMS; do
             sh build.sh "$platform-swift"
         done
@@ -591,12 +595,12 @@ case "$COMMAND" in
         ;;
 
     "test-ios")
-        xctest Realm -configuration "$CONFIGURATION" -sdk iphonesimulator -destination 'name=iPhone 14'
+        xctest Realm -configuration "$CONFIGURATION" -sdk iphonesimulator -destination "name=$(iphone_name)"
         exit 0
         ;;
 
     "test-ios-swift")
-        xctest RealmSwift -configuration "$CONFIGURATION" -sdk iphonesimulator -destination 'name=iPhone 14'
+        xctest RealmSwift -configuration "$CONFIGURATION" -sdk iphonesimulator -destination "name=$(iphone_name)"
         exit 0
         ;;
 
@@ -665,7 +669,7 @@ case "$COMMAND" in
         ;;
 
     "test-ios-swiftui")
-        xctest 'SwiftUITestHost' -configuration "$CONFIGURATION" -sdk iphonesimulator -destination 'name=iPhone 14'
+        xctest 'SwiftUITestHost' -configuration "$CONFIGURATION" -sdk iphonesimulator -destination "name=$(iphone_name)"
         exit 0
         ;;
 
@@ -1062,6 +1066,10 @@ case "$COMMAND" in
         export sha="$BRANCH"
         export REALM_EXTRA_BUILD_ARGUMENTS='GCC_GENERATE_DEBUGGING_SYMBOLS=NO -allowProvisioningUpdates'
         target=$(echo "$CI_WORKFLOW" | cut -f1 -d_)
+        if [[ "$target" == visionos ]] && (( $(xcode_version_major) < 16 )); then
+            echo 'Installing visionOS'
+            xcodebuild -downloadPlatform visionOS
+        fi
         sh build.sh "verify-$target"
         ;;
 
diff --git a/scripts/pr-ci-matrix.rb b/scripts/pr-ci-matrix.rb
index 491c4360dc..c3c42c5bbb 100755
--- a/scripts/pr-ci-matrix.rb
+++ b/scripts/pr-ci-matrix.rb
@@ -82,9 +82,10 @@ def minimum_version(major)
     if not filter.call(version)
       next
     end
-      output_file << """
+    image = version.start_with?('16') ? 'macos-15' : 'macos-14'
+    output_file << """
   #{name}-#{version.gsub(' ', '_').gsub('.', '_')}:
-    runs-on: macos-14
+    runs-on: #{image}
     name: Test #{name} on Xcode #{version}
     env:
       DEVELOPER_DIR: '/Applications/Xcode_#{version}.app/Contents/Developer'