diff --git a/.github/workflows/release-binaries.yml b/.github/workflows/release-binaries.yml
index 85c8f89..ac5fbbe 100644
--- a/.github/workflows/release-binaries.yml
+++ b/.github/workflows/release-binaries.yml
@@ -539,10 +539,18 @@ jobs:
               "aarch64/${binary}-aarch64-apple-darwin" \
               -output "universal/${binary}-universal-apple-darwin"
             chmod 755 "universal/${binary}-universal-apple-darwin"
-            # Xcode 16.4 lipo requires the input file before the
-            # -verify_arch command/arch flags; the legacy flags-first order
-            # parses the file path as an architecture and fails.
-            lipo "universal/${binary}-universal-apple-darwin" -verify_arch x86_64 arm64
+            # Newer lipo (Xcode 27) rejects several architectures in one
+            # -verify_arch ("requires exactly one input file"), and the
+            # input file must precede the flags: verify each architecture
+            # separately, then require exactly the two slices.
+            for arch in x86_64 arm64; do
+              lipo "universal/${binary}-universal-apple-darwin" -verify_arch "$arch"
+            done
+            archs="$(lipo -archs "universal/${binary}-universal-apple-darwin")"
+            [ "$(printf '%s' "$archs" | tr ' ' '\n' | LC_ALL=C sort | tr '\n' ' ')" = "arm64 x86_64 " ] || {
+              echo "unexpected architectures: $archs" >&2
+              exit 1
+            }
           done
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
diff --git a/.github/workflows/release-mcp.yml b/.github/workflows/release-mcp.yml
index d825ba5..1139e78 100644
--- a/.github/workflows/release-mcp.yml
+++ b/.github/workflows/release-mcp.yml
@@ -269,8 +269,17 @@ jobs:
             aarch64/terraphim_mcp_server-aarch64-apple-darwin \
             -output "$out"
           chmod 755 "$out"
-          # The input file must precede -verify_arch with Xcode 16.4 lipo.
-          lipo "$out" -verify_arch x86_64 arm64
+          # Newer lipo (Xcode 27) rejects several architectures in one
+          # -verify_arch ("requires exactly one input file"): verify each
+          # separately, then require exactly the two slices.
+          for arch in x86_64 arm64; do
+            lipo "$out" -verify_arch "$arch"
+          done
+          archs="$(lipo -archs "$out")"
+          [ "$(printf '%s' "$archs" | tr ' ' '\n' | LC_ALL=C sort | tr '\n' ' ')" = "arm64 x86_64 " ] || {
+            echo "unexpected architectures: $archs" >&2
+            exit 1
+          }
           scripts/validate_release_binary.py universal-apple-darwin "$out"
           reported="$("$out" --version | tail -n1 | awk '{print $NF}')"
           [ "$reported" = "$CRATE_VERSION" ] || {
diff --git a/tests/test_release_binaries_workflow_contract.py b/tests/test_release_binaries_workflow_contract.py
index fb6a08f..ace1ec1 100644
--- a/tests/test_release_binaries_workflow_contract.py
+++ b/tests/test_release_binaries_workflow_contract.py
@@ -484,28 +484,31 @@ def test_managed_package_job_and_seal_gates_fail_closed(self) -> None:
                     self.assert_seal_package_result_contract(mutant)
 
     def assert_lipo_verify_arch_order(self, block: str) -> None:
-        # Xcode 16.4 lipo requires the input file before the -verify_arch
-        # command and its architecture flags: the legacy order
-        # `lipo -verify_arch x86_64 arm64 FILE` parses FILE as an
-        # architecture and fails the universal macOS step. The only safe
-        # order is `lipo FILE -verify_arch x86_64 arm64`.
+        # Newer lipo (Xcode 27) rejects several architectures in a single
+        # -verify_arch ("requires exactly one input file"), and the input file
+        # must precede the flags. Verify each architecture on its own, then
+        # require exactly the two slices from `lipo -archs`.
+        self.assertIn("for arch in x86_64 arm64; do", block)
         self.assertIn(
-            'lipo "universal/${binary}-universal-apple-darwin" -verify_arch x86_64 arm64',
-            block,
+            'lipo "universal/${binary}-universal-apple-darwin" -verify_arch "$arch"', block
         )
-        self.assertNotIn("lipo -verify_arch x86_64 arm64", block)
+        self.assertIn('lipo -archs "universal/${binary}-universal-apple-darwin"', block)
+        self.assertIn('= "arm64 x86_64 "', block)
+        self.assertNotIn("-verify_arch x86_64 arm64", block)
+        self.assertNotIn("lipo -verify_arch", block)
 
     def test_universal_lipo_verify_arch_uses_safe_argument_order(self) -> None:
         block = job_block("create-universal-macos")
         self.assert_lipo_verify_arch_order(block)
 
+        safe = 'lipo "universal/${binary}-universal-apple-darwin" -verify_arch "$arch"'
         mutations = {
             "flags-first": block.replace(
-                'lipo "universal/${binary}-universal-apple-darwin" -verify_arch x86_64 arm64',
-                'lipo -verify_arch x86_64 arm64 "universal/${binary}-universal-apple-darwin"',
-                1,
+                safe, 'lipo -verify_arch "$arch" "universal/${binary}-universal-apple-darwin"', 1
             ),
-            "verify-dropped": block.replace(" -verify_arch x86_64 arm64", "", 1),
+            "multi-arch": block.replace(safe, safe.replace('"$arch"', "x86_64 arm64"), 1),
+            "verify-dropped": block.replace(safe, "true", 1),
+            "archs-check-dropped": block.replace('= "arm64 x86_64 "', '= ""', 1),
         }
         for name, mutant in mutations.items():
             with self.subTest(mutation=name):
diff --git a/tests/test_release_mcp_workflow_contract.py b/tests/test_release_mcp_workflow_contract.py
index a2b5ea6..ca900bc 100644
--- a/tests/test_release_mcp_workflow_contract.py
+++ b/tests/test_release_mcp_workflow_contract.py
@@ -159,6 +159,34 @@ def test_assembled_artefact_preserves_the_assets_directory(self) -> None:
         self.assertIn("test -d release/assets", publish)
         self.assertIn("test -s release/checksums.txt", publish)
 
+    @staticmethod
+    def assert_lipo_verification(block: str) -> None:
+        # Newer lipo rejects several architectures in one -verify_arch and
+        # wants the file first: verify each separately, then require exactly
+        # the two slices.
+        assert "for arch in x86_64 arm64; do" in block
+        assert 'lipo "$out" -verify_arch "$arch"' in block
+        assert 'lipo -archs "$out"' in block
+        assert '= "arm64 x86_64 "' in block
+        assert "-verify_arch x86_64 arm64" not in block
+        assert "lipo -verify_arch" not in block
+
+    def test_universal_binary_verifies_each_architecture_separately(self) -> None:
+        block = job_block("universal-macos")
+        self.assert_lipo_verification(block)
+        safe = 'lipo "$out" -verify_arch "$arch"'
+        mutations = {
+            "flags-first": block.replace(safe, 'lipo -verify_arch "$arch" "$out"', 1),
+            "multi-arch": block.replace(safe, 'lipo "$out" -verify_arch x86_64 arm64', 1),
+            "verify-dropped": block.replace(safe, "true", 1),
+            "archs-check-dropped": block.replace('= "arm64 x86_64 "', '= ""', 1),
+        }
+        for name, mutant in mutations.items():
+            with self.subTest(mutation=name):
+                self.assertNotEqual(mutant, block)
+                with self.assertRaises(AssertionError):
+                    self.assert_lipo_verification(mutant)
+
     def test_source_is_trusted_before_any_self_hosted_job(self) -> None:
         preflight = job_block("preflight")
         self.assertIn('git merge-base --is-ancestor "$SOURCE_SHA" origin/main', preflight)