diff --git a/nova/scheduler/utils.py b/nova/scheduler/utils.py
index 601f35d3f1f2..16008f4c82ab 100644
--- a/nova/scheduler/utils.py
+++ b/nova/scheduler/utils.py
@@ -343,6 +343,12 @@ def resources_from_request_spec(spec_obj):
     if 'force_nodes' in spec_obj and spec_obj.force_nodes:
         res_req._limit = None
 
+    # Don't limit allocation candidates when using affinity/anti-affinity.
+    if ('scheduler_hints' in spec_obj and any(
+        key in ['group', 'same_host', 'different_host']
+        for key in spec_obj.scheduler_hints)):
+        res_req._limit = None
+
     return res_req
 
 
diff --git a/nova/tests/unit/scheduler/test_utils.py b/nova/tests/unit/scheduler/test_utils.py
index 7a09731131cf..e92dd111cd4e 100644
--- a/nova/tests/unit/scheduler/test_utils.py
+++ b/nova/tests/unit/scheduler/test_utils.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import ddt
 import mock
 
 from nova.api.openstack.placement import lib as plib
@@ -23,6 +24,7 @@ from nova.tests.unit import fake_instance
 from nova.tests import uuidsentinel as uuids
 
 
+@ddt.ddt
 class TestUtils(test.NoDBTestCase):
 
     def setUp(self):
@@ -35,6 +37,7 @@ class TestUtils(test.NoDBTestCase):
         self.assertEqual(set(ex_by_id), set(ob_by_id))
         for ident in ex_by_id:
             self.assertEqual(vars(ex_by_id[ident]), vars(ob_by_id[ident]))
+        self.assertEqual(expected._limit, observed._limit)
 
     def _test_resources_from_request_spec(self, flavor, expected):
         fake_spec = objects.RequestSpec(flavor=flavor)
@@ -299,6 +302,38 @@ class TestUtils(test.NoDBTestCase):
         resources = utils.resources_from_request_spec(fake_spec)
         self.assertEqual(expected._limit, resources._limit)
 
+    @ddt.data(
+        # Test single hint that we are checking for.
+        {'group': [uuids.fake]},
+        # Test hint we care about and some other random hint.
+        {'same_host': [uuids.fake], 'fake-hint': ['fake-value']},
+        # Test multiple hints we are checking for.
+        {'same_host': [uuids.server1], 'different_host': [uuids.server2]})
+    def test_resources_from_request_spec_no_limit_based_on_hint(self, hints):
+        """Tests that there is no limit applied to the
+        GET /allocation_candidates query string if a given scheduler hint
+        is in the request spec.
+        """
+        flavor = objects.Flavor(vcpus=1,
+                                memory_mb=1024,
+                                root_gb=15,
+                                ephemeral_gb=0,
+                                swap=0)
+        fake_spec = objects.RequestSpec(
+            flavor=flavor, scheduler_hints=hints)
+        expected = utils.ResourceRequest()
+        expected._rg_by_id[None] = plib.RequestGroup(
+            use_same_provider=False,
+            resources={
+                'VCPU': 1,
+                'MEMORY_MB': 1024,
+                'DISK_GB': 15,
+            },
+        )
+        expected._limit = None
+        resources = utils.resources_from_request_spec(fake_spec)
+        self.assertResourceRequestsEqual(expected, resources)
+
     @mock.patch('nova.compute.utils.is_volume_backed_instance',
                 return_value=False)
     def test_resources_from_flavor_no_bfv(self, mock_is_bfv):