diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 718b588040eb..91986c58386b 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -31,7 +31,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos-14
+          - os: macos-15
             label: macOS (Apple silicon)
             slug: macos-arm64
           - os: macos-13
@@ -43,9 +43,18 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # The Xcode a runner happens to ship is too old for this codebase —
+      # AppleClang 15 lacks CTAD for aggregates, which src/util/overloaded.h
+      # requires. Homebrew's LLVM is current on every image, so build with that
+      # rather than depending on the runner's Xcode vintage.
       - name: Dependencies (macOS)
         if: runner.os == 'macOS'
-        run: brew install cmake ninja boost capnp
+        run: |
+          brew install cmake ninja boost capnp llvm
+          PREFIX=$(brew --prefix llvm)
+          echo "CC=$PREFIX/bin/clang"    >> "$GITHUB_ENV"
+          echo "CXX=$PREFIX/bin/clang++" >> "$GITHUB_ENV"
+          "$PREFIX/bin/clang++" --version | head -1
 
       - name: Dependencies (Linux)
         if: runner.os == 'Linux'
diff --git a/contrib/vibes/bitcoin-vibes b/contrib/vibes/bitcoin-vibes
index a0e163f7e30b..64e5d8580651 100755
--- a/contrib/vibes/bitcoin-vibes
+++ b/contrib/vibes/bitcoin-vibes
@@ -1599,6 +1599,20 @@ class Console:
                       ("Darwin", "x86_64"): "macos-x86_64",
                       ("Linux", "x86_64"): "linux-x86_64"}
 
+    @staticmethod
+    def host_machine():
+        """The machine's architecture, not the interpreter's.
+
+        A Python built for x86_64 running under Rosetta on Apple silicon reports
+        x86_64, which would fetch an Intel node for an ARM Mac. Ask the kernel
+        whether we are translated and answer for the hardware."""
+        mach = platform.machine()
+        if sys.platform == "darwin" and mach == "x86_64":
+            code, out, _ = run(["sysctl", "-n", "sysctl.proc_translated"], timeout=10)
+            if code == 0 and out.strip() == "1":
+                return "arm64"
+        return mach
+
     def try_prebuilt(self, job):
         """Fetch a published node, but only one built from this exact commit.
 
@@ -1607,7 +1621,7 @@ class Console:
         than quietly running the wrong thing."""
         if os.environ.get("VIBES_NO_PREBUILT") == "1":
             return False
-        slug = self.PREBUILT_SLUGS.get((platform.system(), platform.machine()))
+        slug = self.PREBUILT_SLUGS.get((platform.system(), self.host_machine()))
         if not slug:
             return False
         _, head, _ = self.git("rev-parse", "HEAD")