diff --git a/subiquity/server/server.py b/subiquity/server/server.py
index f88d5f425..e11489f78 100644
--- a/subiquity/server/server.py
+++ b/subiquity/server/server.py
@@ -668,9 +668,28 @@ def _read_config(self, *, cfg_path: str, context: Context) -> dict[str, Any]:
         with open(cfg_path) as fp:
             config: dict[str, Any] = yaml.safe_load(fp)
 
-        autoinstall_config: dict[str, Any] = dict()
+        autoinstall_config: dict[str, Any]
+
+        # Support "autoinstall" as a top-level key
+        if "autoinstall" in config:
+            autoinstall_config = config.pop("autoinstall")
+
+            # but the only top level key
+            if len(config) != 0:
+                self.interactive = bool(autoinstall_config.get("interactive-sections"))
+                msg: str = (
+                    "autoinstall.yaml is not a valid cloud config datasource.\n"
+                    "No other keys may be present alongside 'autoinstall' at "
+                    "the top level."
+                )
+                context.error(msg)
+                raise AutoinstallValidationError(
+                    owner="top-level keys",
+                    details="autoinstall.yaml is not a valid cloud config datasource",
+                )
 
-        autoinstall_config = config
+        else:
+            autoinstall_config = config
 
         return autoinstall_config
 
diff --git a/subiquity/server/tests/test_server.py b/subiquity/server/tests/test_server.py
index a6a199f3e..ec3069a55 100644
--- a/subiquity/server/tests/test_server.py
+++ b/subiquity/server/tests/test_server.py
@@ -19,6 +19,7 @@
 from unittest.mock import AsyncMock, Mock, patch
 
 import jsonschema
+import yaml
 from jsonschema.validators import validator_for
 
 from subiquity.common.types import NonReportableError, PasswordKind
@@ -154,6 +155,7 @@ def test_early_commands_changes_autoinstall(self, validate_mock):
 
 class TestAutoinstallValidation(SubiTestCase):
     async def asyncSetUp(self):
+        self.tempdir = self.tmp_dir()
         opts = Mock()
         opts.dry_run = True
         opts.output_base = self.tmp_dir()
@@ -169,6 +171,15 @@ async def asyncSetUp(self):
         }
         self.server.make_apport_report = Mock()
 
+    def path(self, relative_path):
+        return self.tmp_path(relative_path, dir=self.tempdir)
+
+    def create(self, path, contents):
+        path = self.path(path)
+        with open(path, "w") as fp:
+            fp.write(contents)
+        return path
+
     # Pseudo Load Controllers to avoid patching the loading logic for each
     # controller when we still want access to class attributes
     def pseudo_load_controllers(self):
@@ -357,6 +368,44 @@ async def test_autoinstall_validation__filter_autoinstall(self, config, good, ba
         self.assertEqual(valid, good)
         self.assertEqual(invalid, bad)
 
+    async def test_autoinstall_validation__top_level_autoinstall(self):
+        """Test allow autoinstall as top-level key"""
+
+        new_style = {
+            "autoinstall": {
+                "version": 1,
+                "interactive-sections": ["identity"],
+                "apt": "...",
+            }
+        }
+        old_style = new_style["autoinstall"]
+
+        # Read new style correctly
+        path = self.create("autoinstall.yaml", yaml.dump(new_style))
+        self.assertEqual(self.server._read_config(cfg_path=path), old_style)
+
+        # No changes to old style
+        path = self.create("autoinstall.yaml", yaml.dump(old_style))
+        self.assertEqual(self.server._read_config(cfg_path=path), old_style)
+
+    async def test_autoinstall_validation__not_cloudinit_datasource(self):
+        """Test no cloud init datasources in new style autoinstall"""
+
+        new_style = {
+            "autoinstall": {
+                "version": 1,
+                "interactive-sections": ["identity"],
+                "apt": "...",
+            },
+            "cloudinit-data": "I am data",
+        }
+
+        with self.assertRaises(AutoinstallValidationError) as ctx:
+            path = self.create("autoinstall.yaml", yaml.dump(new_style))
+            self.server._read_config(cfg_path=path)
+
+        self.assertEqual("top-level keys", ctx.exception.owner)
+
 
 class TestMetaController(SubiTestCase):
     async def test_interactive_sections_not_present(self):