diff --git a/tools/asset_pipeline/setup_state.py b/tools/asset_pipeline/setup_state.py
index 28f3ed71..5824e97d 100644
--- a/tools/asset_pipeline/setup_state.py
+++ b/tools/asset_pipeline/setup_state.py
@@ -57,6 +57,10 @@ def sha(path):
 
 
 def receipt(root, paths):
+    # Windows short names and directory junctions must use the same spelling
+    # on both sides of relative_to; also reject outputs outside the root.
+    root = root.resolve()
+    paths = (p.resolve() for p in paths)
     return {p.relative_to(root).as_posix(): {'size': p.stat().st_size, 'sha256': sha(p)}
             for p in sorted(set(paths)) if p.is_file()}
 
diff --git a/tools/asset_pipeline/test_setup_recovery.py b/tools/asset_pipeline/test_setup_recovery.py
index 135cc369..3acc3899 100644
--- a/tools/asset_pipeline/test_setup_recovery.py
+++ b/tools/asset_pipeline/test_setup_recovery.py
@@ -14,6 +14,25 @@ from .setup_state import source_directory, setup_lock, receipt, valid_receipt
 
 
 class SetupRecovery(unittest.TestCase):
+    @unittest.skipUnless(os.name == 'nt', 'Windows directory aliases')
+    def test_receipts_accept_windows_aliases_but_reject_outside_files(self):
+        import _winapi
+        with tempfile.TemporaryDirectory() as temp:
+            root = Path(temp).resolve()
+            target = root/'long installation directory';target.mkdir()
+            alias = root/'alias'
+            _winapi.CreateJunction(str(target),str(alias))
+            try:
+                payload = target/'map.skate';payload.write_bytes(b'map')
+                expected = receipt(target,[payload])
+                self.assertEqual(receipt(alias,[payload]),expected)
+                self.assertEqual(receipt(target,[alias/'map.skate']),expected)
+                self.assertTrue(valid_receipt(alias,expected))
+                outside = root/'outside';outside.write_bytes(b'outside')
+                with self.assertRaises(ValueError):receipt(alias,[outside])
+            finally:
+                alias.rmdir()  # Remove the junction, never its target.
+
     def test_xex_refresh_failure_never_publishes_core_or_edits_user_data(self):
         with tempfile.TemporaryDirectory() as temp:
             base, old, source, current, marker = test_versions.AssetVersions().fixture(Path(temp))