diff --git a/bumble/drivers/rtk.py b/bumble/drivers/rtk.py
index e7e476d6..c332bf09 100644
--- a/bumble/drivers/rtk.py
+++ b/bumble/drivers/rtk.py
@@ -499,7 +499,9 @@ class Driver(common.Driver):
     async def driver_info_for_host(cls, host):
         try:
             await host.send_command(
-                HCI_Reset_Command(), check_result=True, response_timeout=cls.POST_RESET_DELAY
+                HCI_Reset_Command(),
+                check_result=True,
+                response_timeout=cls.POST_RESET_DELAY,
             )
             host.ready = True  # Needed to let the host know the controller is ready.
         except asyncio.exceptions.TimeoutError:
diff --git a/bumble/host.py b/bumble/host.py
index 1abefd90..6c2c350a 100644
--- a/bumble/host.py
+++ b/bumble/host.py
@@ -514,7 +514,9 @@ class Host(AbortableEventEmitter):
         if self.hci_sink:
             self.hci_sink.on_packet(bytes(packet))
 
-    async def send_command(self, command, check_result=False, response_timeout: Optional[int] = None):
+    async def send_command(
+        self, command, check_result=False, response_timeout: Optional[int] = None
+    ):
         # Wait until we can send (only one pending command at a time)
         async with self.command_semaphore:
             assert self.pending_command is None