diff --git a/nova/api/openstack/placement/handlers/allocation.py b/nova/api/openstack/placement/handlers/allocation.py
index 545957c29e29..2105ef28c8ea 100644
--- a/nova/api/openstack/placement/handlers/allocation.py
+++ b/nova/api/openstack/placement/handlers/allocation.py
@@ -32,6 +32,7 @@ ALLOCATION_SCHEMA = {
     "properties": {
         "allocations": {
             "type": "array",
+            "minItems": 1,
             "items": {
                 "type": "object",
                 "properties": {
diff --git a/nova/tests/functional/api/openstack/placement/gabbits/allocations.yaml b/nova/tests/functional/api/openstack/placement/gabbits/allocations.yaml
index 86b6e7072118..e91ebb80b059 100644
--- a/nova/tests/functional/api/openstack/placement/gabbits/allocations.yaml
+++ b/nova/tests/functional/api/openstack/placement/gabbits/allocations.yaml
@@ -48,6 +48,16 @@ tests:
       content-type: application/json
   status: 400
 
+- name: put an allocation empty list
+  PUT: /allocations/599ffd2d-526a-4b2e-8683-f13ad25f9958
+  request_headers:
+      content-type: application/json
+  data:
+      allocations: []
+  status: 400
+  response_strings:
+      - "Failed validating 'minItems'"
+
 - name: put an allocation violate schema
   PUT: /allocations/599ffd2d-526a-4b2e-8683-f13ad25f9958
   request_headers: