diff --git a/cinder/scheduler/host_manager.py b/cinder/scheduler/host_manager.py
index c4cc3edc706..1ddfcacf5e7 100644
--- a/cinder/scheduler/host_manager.py
+++ b/cinder/scheduler/host_manager.py
@@ -114,7 +114,7 @@ class BackendState(object):
 
         self.volume_backend_name = None
         self.vendor_name = None
-        self.driver_version = 0
+        self.driver_version: Optional[int] = 0
         self.storage_protocol = None
         self.QoS_support = False
         # Mutable available resources.
@@ -259,6 +259,8 @@ class BackendState(object):
                 # To get DEFAULT_POOL_NAME
                 pool_name = volume_utils.extract_host(self.host, 'pool', True)
 
+            pool_name = typing.cast(str, pool_name)
+
             if len(self.pools) == 0:
                 # No pool was there
                 single_pool = self.pool_state_cls(self.host, self.cluster_name,
diff --git a/test-requirements.txt b/test-requirements.txt
index 70e647ed5eb..54d087843ac 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -18,6 +18,6 @@ SQLAlchemy-Utils>=0.37.8 # BSD License
 testtools>=2.4.0 # MIT
 
 doc8>=0.8.1 # Apache-2.0
-mypy>=1.7.0,<1.16.0 # MIT
+mypy>=1.7.0,<1.17.0 # MIT
 moto>=5.0.0 # Apache-2.0
 distro>=1.8.0 # Apache-2.0