diff --git a/nova/tests/unit/virt/libvirt/test_host.py b/nova/tests/unit/virt/libvirt/test_host.py
index 1abb0458abed..20279a91a239 100644
--- a/nova/tests/unit/virt/libvirt/test_host.py
+++ b/nova/tests/unit/virt/libvirt/test_host.py
@@ -1970,4 +1970,4 @@ class LoadersTestCase(test.NoDBTestCase):
             ])
             mock_glob.assert_called_once_with(
                 '/usr/share/qemu/firmware/*.json')
-            mock_open.assert_called_once_with('10_fake.json')
+            mock_open.assert_called_once_with('10_fake.json', 'rb')
diff --git a/nova/virt/libvirt/host.py b/nova/virt/libvirt/host.py
index 2321501be912..1de93137b590 100644
--- a/nova/virt/libvirt/host.py
+++ b/nova/virt/libvirt/host.py
@@ -108,7 +108,7 @@ def _get_loaders():
             continue
 
         for spec_path in sorted(glob.glob(f'{path}/*.json')):
-            with open(spec_path) as fh:
+            with open(spec_path, 'rb') as fh:
                 spec = jsonutils.load(fh)
 
             _loaders.append(spec)