diff --git a/kitty/boss.py b/kitty/boss.py
index 88cdfb3d3..c0a01ec4b 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -359,7 +359,7 @@ class Boss:
             self.allow_remote_control = 'y'
         elif self.allow_remote_control in ('n', 'no', 'false'):
             self.allow_remote_control = 'n'
-        self.listening_on = ''
+        self.listening_on: str = ''
         listen_fd = -1
         if args.listen_on and self.allow_remote_control in ('y', 'socket', 'socket-only', 'password'):
             try:
@@ -367,15 +367,15 @@ class Boss:
             except Exception:
                 self.misc_config_errors.append(f'Invalid listen_on={args.listen_on}, ignoring')
                 log_error(self.misc_config_errors[-1])
-        self.child_monitor = ChildMonitor(
+        self.child_monitor: ChildMonitor = ChildMonitor(
             self.on_child_death,
             DumpCommands(args) if args.dump_commands or args.dump_bytes else None,
             talk_fd, listen_fd,
         )
         set_boss(self)
-        self.args = args
+        self.args: CLIOptions = args
         self.mouse_handler: Optional[Callable[[WindowSystemMouseEvent], None]] = None
-        self.mappings = Mappings(global_shortcuts, self.refresh_active_tab_bar)
+        self.mappings: Mappings = Mappings(global_shortcuts, self.refresh_active_tab_bar)
         if is_macos:
             from .fast_data_types import cocoa_set_notification_activated_callback
             cocoa_set_notification_activated_callback(notification_activated)