diff --git a/.github/workflows/mobile-ios-release.yml b/.github/workflows/mobile-ios-release.yml
index ea9ac818f..0dfc62965 100644
--- a/.github/workflows/mobile-ios-release.yml
+++ b/.github/workflows/mobile-ios-release.yml
@@ -11,11 +11,11 @@ on:
 
 jobs:
   ios-build:
-    # GitHub-hosted macOS runner: required for Xcode. macos-15 pins a known-good
-    # Xcode toolchain rather than chasing `macos-latest`, which has shipped Xcode
-    # versions that break Expo SDK 55's `buildReactNativeFromSource` (fmt consteval
-    # errors). Bump deliberately after testing a new image.
-    runs-on: macos-15
+    # GitHub-hosted macOS runner: required for Xcode. Expo SDK 55's
+    # expo-modules-core declares swift_version 6.0 and uses Swift 6 syntax
+    # (@MainActor isolation). Xcode 16.x (macos-15) can't even parse it
+    # ("unknown attribute 'MainActor'"), so we need Xcode 26.x → macos-26.
+    runs-on: macos-26
 
     defaults:
       run:
@@ -28,7 +28,8 @@ jobs:
       - name: Select Xcode
         uses: maxim-lobanov/setup-xcode@v1
         with:
-          xcode-version: '16.4'
+          # Xcode 26.x ships the Swift 6.x toolchain Expo SDK 55 requires.
+          xcode-version: '26.5'
 
       - name: Setup Node.js
         uses: actions/setup-node@v6