diff --git a/nova/scheduler/host_manager.py b/nova/scheduler/host_manager.py
index 6fcd979a5fb3..4feffe4530b8 100644
--- a/nova/scheduler/host_manager.py
+++ b/nova/scheduler/host_manager.py
@@ -376,7 +376,7 @@ class HostManager(object):
         for agg in aggs:
             self.aggs_by_id[agg.id] = agg
             for host in agg.hosts:
-                self.host_aggregates_map[host].add(agg.id)
+                self.host_aggregates_map[host.lower()].add(agg.id)
 
     def update_aggregates(self, aggregates):
         """Updates internal HostManager information about aggregates."""
@@ -395,7 +395,7 @@ class HostManager(object):
         for host in self.host_aggregates_map:
             if (aggregate.id in self.host_aggregates_map[host]
                     and host not in aggregate.hosts):
-                self.host_aggregates_map[host].remove(aggregate.id)
+                self.host_aggregates_map[host.lower()].remove(aggregate.id)
 
     def delete_aggregate(self, aggregate):
         """Deletes internal HostManager information about a specific aggregate.
@@ -714,7 +714,7 @@ class HostManager(object):
 
     def _get_aggregates_info(self, host):
         return [self.aggs_by_id[agg_id] for agg_id in
-                self.host_aggregates_map[host]]
+                self.host_aggregates_map[host.lower()]]
 
     def _get_instances_by_host(self, context, host_name):
         try:
diff --git a/nova/tests/unit/scheduler/test_host_manager.py b/nova/tests/unit/scheduler/test_host_manager.py
index 42a263c3234f..c147780ff12f 100644
--- a/nova/tests/unit/scheduler/test_host_manager.py
+++ b/nova/tests/unit/scheduler/test_host_manager.py
@@ -173,6 +173,17 @@ class HostManagerTestCase(test.NoDBTestCase):
         self.assertEqual({'fake-host': set([1])},
                          self.host_manager.host_aggregates_map)
 
+    @mock.patch.object(host_manager.HostManager, '_init_instance_info')
+    @mock.patch.object(objects.AggregateList, 'get_all')
+    def test_init_aggregates_one_agg_with_hosts_upper_case(self, agg_get_all,
+                                                           mock_init_info):
+        fake_agg = objects.Aggregate(id=1, hosts=['FAKE-host'])
+        agg_get_all.return_value = [fake_agg]
+        self.host_manager = host_manager.HostManager()
+        self.assertEqual({1: fake_agg}, self.host_manager.aggs_by_id)
+        self.assertEqual({'fake-host': set([1])},
+                         self.host_manager.host_aggregates_map)
+
     def test_update_aggregates(self):
         fake_agg = objects.Aggregate(id=1, hosts=['fake-host'])
         self.host_manager.update_aggregates([fake_agg])