diff --git a/errors/silent-failures/macos-latest-upgraded-to-macos-15-xcode-16-swift-6.yml b/errors/silent-failures/macos-latest-upgraded-to-macos-15-xcode-16-swift-6.yml
index 95afb67..63e1747 100644
--- a/errors/silent-failures/macos-latest-upgraded-to-macos-15-xcode-16-swift-6.yml
+++ b/errors/silent-failures/macos-latest-upgraded-to-macos-15-xcode-16-swift-6.yml
@@ -28,8 +28,9 @@ root_cause: |
   appear to run normally until the Swift compiler raises concurrency errors on previously clean code.
   This mirrors the ubuntu-latest → ubuntu-24.04 silent label change (see silent-failures-059).
 fix: |
-  Option 1 — Pin to macos-14 until your codebase is Swift 6 ready:
-    runs-on: macos-14
+  Option 1 — Pin to macos-15 until your codebase is Swift 6 ready:
+    runs-on: macos-15
+    Note: macOS 14 deprecation begins July 6, 2026 — do NOT pin to macos-14.
   
   Option 2 — Disable strict concurrency checking temporarily:
     Add SWIFT_STRICT_CONCURRENCY=minimal to xcodebuild arguments.
@@ -39,12 +40,13 @@ fix: |
     Use async/await and actors for shared mutable state.
 fix_code:
   - language: yaml
-    label: "Pin to macos-14 until Swift 6 migration is complete"
+    label: "Pin to macos-15 until Swift 6 migration is complete (macos-14 deprecated July 2026)"
     code: |
       jobs:
         build:
-          runs-on: macos-14  # Pinned — avoids Xcode 16 Swift 6 strictness
-          # Use macos-15 once concurrency issues are resolved
+          # Pin to macos-15 — avoids Xcode 16 Swift 6 strictness from macos-latest
+          # DO NOT pin to macos-14: deprecated starting July 6, 2026 (retired Nov 2, 2026)
+          runs-on: macos-15
           steps:
             - uses: actions/checkout@v4
             - name: Build and test
@@ -58,7 +60,7 @@ fix_code:
             -scheme MyApp \
             SWIFT_STRICT_CONCURRENCY=minimal
 prevention:
-  - "Pin to a specific macOS version (macos-14, macos-15) instead of macos-latest for stability"
+  - "Pin to a specific macOS version (macos-15, macos-26) instead of macos-latest for stability; do NOT use macos-14 as it is deprecated starting July 6, 2026"
   - "Follow GitHub Changelog for macos-latest label change announcements before they happen"
   - "Run Xcode 16 locally with Swift strict concurrency enabled before CI failures surface"
   - "Add a step printing runner OS version (sw_vers) to detect unexpected runner upgrades"