diff --git a/scripts/model-invariants.mjs b/scripts/model-invariants.mjs
index a20fab68..ab10d0f8 100644
--- a/scripts/model-invariants.mjs
+++ b/scripts/model-invariants.mjs
@@ -225,7 +225,7 @@ export function checkReferences({ config, layout = {} } = {}, { notes = [] } = {
             'комнаты назначения не существует в том же пространстве');
         }
       }
-      if (Number(config?.model_version || 0) >= 8) {
+      if (Number(config?.model_version || 0) === 8) {
         const wallIds = Array.isArray(room?.wall_ids) ? room.wall_ids : [];
         const poly = roomPolygon(room) || [];
         if (wallIds.length !== poly.length) {
@@ -246,7 +246,11 @@ export function checkReferences({ config, layout = {} } = {}, { notes = [] } = {
     for (const opening of space?.openings || []) {
       const host = opening?.host;
       if (!host) {
-        if (Number(config?.model_version || 0) >= 8) {
+        // #316 §3.3: since model v9 an unhosted contour opening is a valid
+        // degraded state (the migration keeps an opening with no in-place
+        // carrier as data, inert until re-placed). Only model v8 documents
+        // still require an explicit host on every opening.
+        if (Number(config?.model_version || 0) === 8) {
           add('opening_host', `${spaceId}:${opening?.id ?? '?'}`, '?',
             'в model v8 у проёма нет явной стены-хоста');
         }
diff --git a/test/model-invariants.test.mjs b/test/model-invariants.test.mjs
index ea467155..93483120 100644
--- a/test/model-invariants.test.mjs
+++ b/test/model-invariants.test.mjs
@@ -688,3 +688,30 @@ test('реальный план: перегородка поверх наруж
     assert.equal(checkHiddenObstacles(config).length, expected, file);
   }
 });
+
+test('#316: непривязанный контурный проём — валидное состояние v9, но не v8', () => {
+  const base = () => ({
+    config: {
+      model_version: 9,
+      spaces: [{
+        id: 'sp316', title: 'S', view_box: [0, 0, 1, 1],
+        rooms: [], openings: [{
+          id: 'orphan', type: 'door', x: 0.9, y: 0.65, angle: 90, length: 0.05,
+        }],
+      }],
+      markers: [], settings: {},
+    },
+    layout: {},
+  });
+  const v9 = base();
+  assert.deepEqual(
+    checkReferences(v9).filter((item) => item.kind === 'opening_host'), [],
+    'model v9 keeps the unhosted degraded state of #316 §3.3 without a violation',
+  );
+  const v8 = base();
+  v8.config.model_version = 8;
+  assert.equal(
+    checkReferences(v8).filter((item) => item.kind === 'opening_host').length, 1,
+    'model v8 still requires an explicit host on every opening',
+  );
+});