diff --git a/bots/zephyr_mirror.py b/bots/zephyr_mirror.py
index 165badc..38275b5 100755
--- a/bots/zephyr_mirror.py
+++ b/bots/zephyr_mirror.py
@@ -34,9 +34,13 @@ from .zephyr_mirror_backend import parse_args
 (options, args) = parse_args()
 
 sys.path[:0] = [os.path.join(options.root_path, 'api')]
+
+from types import FrameType
 from typing import Any
 
 def die(signal, frame):
+    # type: (int, FrameType) -> None
+
     # We actually want to exit, so run os._exit (so as not to be caught and restarted)
     os._exit(1)
 
@@ -59,6 +63,7 @@ if options.forward_class_messages and not options.noshard:
     print("Starting parallel zephyr class mirroring bot")
     jobs = list("0123456789abcdef")
     def run_job(shard):
+        # type: (str) -> int
         subprocess.call(args + ["--shard=%s" % (shard,)])
         return 0
     for (status, job) in run_parallel(run_job, jobs, threads=16):