diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 62c84f3..0a635f7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,7 +45,7 @@ jobs:
       - run: node Tests/mcp-smoke.mjs
 
   legacy-macos:
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
       - uses: actions/checkout@v4
       - run: swift test