diff --git a/api-ref/source/parameters.yaml b/api-ref/source/parameters.yaml
index 12439a51bc9b..6f666c083d06 100644
--- a/api-ref/source/parameters.yaml
+++ b/api-ref/source/parameters.yaml
@@ -1042,7 +1042,23 @@ sort_key_flavor:
     Sorts by a flavor attribute. Default attribute is ``flavorid``. You can specify
     multiple pairs of sort key and sort direction query parameters. If you omit the
     sort direction in a pair, the API uses the natural sorting direction of the flavor
-    ``sort_key`` attribute.
+    ``sort_key`` attribute. The sort keys are limited to:
+
+    - ``created_at``
+    - ``description``
+    - ``disabled``
+    - ``ephemeral_gb``
+    - ``flavorid``
+    - ``id``
+    - ``is_public``
+    - ``memory_mb``
+    - ``name``
+    - ``root_gb``
+    - ``rxtx_factor``
+    - ``swap``
+    - ``updated_at``
+    - ``vcpu_weight``
+    - ``vcpus``
   in: query
   required: false
   type: string
diff --git a/nova/api/openstack/compute/schemas/flavors.py b/nova/api/openstack/compute/schemas/flavors.py
index 91ca03e5d525..96a6f6b4e80a 100644
--- a/nova/api/openstack/compute/schemas/flavors.py
+++ b/nova/api/openstack/compute/schemas/flavors.py
@@ -13,6 +13,16 @@
 #    under the License.
 from nova.api.validation import parameter_types
 
+# NOTE(takashin): The following sort keys are defined for backward
+# compatibility. If they are changed, the API microversion should be bumped.
+VALID_SORT_KEYS = [
+    'created_at', 'description', 'disabled', 'ephemeral_gb', 'flavorid', 'id',
+    'is_public', 'memory_mb', 'name', 'root_gb', 'rxtx_factor', 'swap',
+    'updated_at', 'vcpu_weight', 'vcpus'
+]
+
+VALID_SORT_DIR = ['asc', 'desc']
+
 index_query = {
     'type': 'object',
     'properties': {
@@ -22,8 +32,10 @@ index_query = {
         'is_public': parameter_types.multi_params({'type': 'string'}),
         'minRam': parameter_types.multi_params({'type': 'string'}),
         'minDisk': parameter_types.multi_params({'type': 'string'}),
-        'sort_key': parameter_types.multi_params({'type': 'string'}),
-        'sort_dir': parameter_types.multi_params({'type': 'string'})
+        'sort_key': parameter_types.multi_params({'type': 'string',
+                                                  'enum': VALID_SORT_KEYS}),
+        'sort_dir': parameter_types.multi_params({'type': 'string',
+                                                  'enum': VALID_SORT_DIR})
     },
     # NOTE(gmann): This is kept True to keep backward compatibility.
     # As of now Schema validation stripped out the additional parameters and
diff --git a/nova/tests/functional/api_sample_tests/test_flavors.py b/nova/tests/functional/api_sample_tests/test_flavors.py
index b2b42975b924..de78d00a52a9 100644
--- a/nova/tests/functional/api_sample_tests/test_flavors.py
+++ b/nova/tests/functional/api_sample_tests/test_flavors.py
@@ -22,6 +22,11 @@ class FlavorsSampleJsonTest(api_sample_base.ApiSampleTestBaseV21):
     sample_dir = 'flavors'
     flavor_show_id = '1'
     subs = {}
+    sort_keys = ['created_at', 'description', 'disabled', 'ephemeral_gb',
+                 'flavorid', 'id', 'is_public', 'memory_mb', 'name',
+                 'root_gb', 'rxtx_factor', 'swap', 'updated_at',
+                 'vcpu_weight', 'vcpus']
+    sort_dirs = ['asc', 'desc']
 
     def test_flavors_get(self):
         response = self._do_get('flavors/%s' % self.flavor_show_id)
@@ -31,11 +36,51 @@ class FlavorsSampleJsonTest(api_sample_base.ApiSampleTestBaseV21):
         response = self._do_get('flavors')
         self._verify_response('flavors-list-resp', self.subs, response, 200)
 
+    def test_flavors_list_with_sort_key(self):
+        for sort_key in self.sort_keys:
+            response = self._do_get('flavors?sort_key=%s' % sort_key)
+            self._verify_response('flavors-list-resp', self.subs, response,
+                                  200)
+
+    def test_flavors_list_with_invalid_sort_key(self):
+        response = self._do_get('flavors?sort_key=invalid')
+        self.assertEqual(400, response.status_code)
+
+    def test_flavors_list_with_sort_dir(self):
+        for sort_dir in self.sort_dirs:
+            response = self._do_get('flavors?sort_dir=%s' % sort_dir)
+            self._verify_response('flavors-list-resp', self.subs, response,
+                                  200)
+
+    def test_flavors_list_with_invalid_sort_dir(self):
+        response = self._do_get('flavors?sort_dir=invalid')
+        self.assertEqual(400, response.status_code)
+
     def test_flavors_detail(self):
         response = self._do_get('flavors/detail')
         self._verify_response('flavors-detail-resp', self.subs, response,
                               200)
 
+    def test_flavors_detail_with_sort_key(self):
+        for sort_key in self.sort_keys:
+            response = self._do_get('flavors/detail?sort_key=%s' % sort_key)
+            self._verify_response('flavors-detail-resp', self.subs, response,
+                                  200)
+
+    def test_flavors_detail_with_invalid_sort_key(self):
+        response = self._do_get('flavors/detail?sort_key=invalid')
+        self.assertEqual(400, response.status_code)
+
+    def test_flavors_detail_with_sort_dir(self):
+        for sort_dir in self.sort_dirs:
+            response = self._do_get('flavors/detail?sort_dir=%s' % sort_dir)
+            self._verify_response('flavors-detail-resp', self.subs, response,
+                                  200)
+
+    def test_flavors_detail_with_invalid_sort_dir(self):
+        response = self._do_get('flavors/detail?sort_dir=invalid')
+        self.assertEqual(400, response.status_code)
+
 
 class FlavorsSampleJsonTest2_55(FlavorsSampleJsonTest):
     microversion = '2.55'