diff --git a/mypy-files.txt b/mypy-files.txt
index 3e5543d0f..bd4f113f2 100644
--- a/mypy-files.txt
+++ b/mypy-files.txt
@@ -16,6 +16,7 @@ os_brick/initiator/host_driver.py
 os_brick/initiator/linuxfc.py
 os_brick/initiator/utils.py
 os_brick/privileged/nvmeof.py
+os_brick/privileged/rbd.py
 os_brick/remotefs/remotefs.py
 os_brick/initiator/linuxrbd.py
 os_brick/encryptors/luks.py
diff --git a/os_brick/privileged/rbd.py b/os_brick/privileged/rbd.py
index 89f4a225e..14799615c 100644
--- a/os_brick/privileged/rbd.py
+++ b/os_brick/privileged/rbd.py
@@ -13,13 +13,15 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import Optional
+
 from oslo_utils import fileutils
 from oslo_utils import importutils
 
 import os_brick.privileged
 
 # Lazy load the rbd module to avoid circular references
-RBDConnector = None
+RBDConnector: Optional['os_brick.initiator.connectors.rbd.RBDConnector'] = None
 
 
 def _get_rbd_class():
@@ -48,6 +50,7 @@ def root_create_ceph_conf(monitor_ips, monitor_ports, cluster_name, user,
                           keyring):
     """Create a .conf file for Ceph cluster only accessible by root."""
     get_rbd_class()
+    assert RBDConnector is not None
     return RBDConnector._create_ceph_conf(monitor_ips, monitor_ports,
                                           cluster_name, user, keyring)
 
@@ -55,5 +58,6 @@ def root_create_ceph_conf(monitor_ips, monitor_ports, cluster_name, user,
 @os_brick.privileged.default.entrypoint
 def check_valid_path(path):
     get_rbd_class()
+    assert RBDConnector is not None
     with open(path, 'rb') as rbd_handle:
         return RBDConnector._check_valid_device(rbd_handle)