diff --git a/zulip/integrations/jabber/jabber_mirror.py b/zulip/integrations/jabber/jabber_mirror.py
index 47cab5b59..5ebb4a4bf 100755
--- a/zulip/integrations/jabber/jabber_mirror.py
+++ b/zulip/integrations/jabber/jabber_mirror.py
@@ -6,11 +6,12 @@
 import sys
 import traceback
 from types import FrameType
+from typing import Optional
 
 from zulip import RandomExponentialBackoff
 
 
-def die(signal: int, frame: FrameType) -> None:
+def die(signal: int, frame: Optional[FrameType]) -> None:
     """We actually want to exit, so run os._exit (so as not to be caught and restarted)"""
     os._exit(1)
 
diff --git a/zulip/integrations/zephyr/zephyr_mirror.py b/zulip/integrations/zephyr/zephyr_mirror.py
index 67f9af528..e0bd91236 100755
--- a/zulip/integrations/zephyr/zephyr_mirror.py
+++ b/zulip/integrations/zephyr/zephyr_mirror.py
@@ -6,16 +6,16 @@
 import subprocess
 import sys
 import traceback
+from types import FrameType
+from typing import Optional
 
 sys.path[:0] = [os.path.dirname(__file__)]
 from zephyr_mirror_backend import parse_args
 
 (options, args) = parse_args()
 
-from types import FrameType
-
 
-def die(signal: int, frame: FrameType) -> None:
+def die(signal: int, frame: Optional[FrameType]) -> None:
     # We actually want to exit, so run os._exit (so as not to be caught and restarted)
     os._exit(1)
 
diff --git a/zulip/integrations/zephyr/zephyr_mirror_backend.py b/zulip/integrations/zephyr/zephyr_mirror_backend.py
index 0b27110ac..8ce1b3476 100755
--- a/zulip/integrations/zephyr/zephyr_mirror_backend.py
+++ b/zulip/integrations/zephyr/zephyr_mirror_backend.py
@@ -1238,7 +1238,7 @@ def parse_args() -> Tuple[optparse.Values, List[str]]:
     return parser.parse_args()
 
 
-def die_gracefully(signal: int, frame: FrameType) -> None:
+def die_gracefully(signal: int, frame: Optional[FrameType]) -> None:
     if CURRENT_STATE == States.ZulipToZephyr:
         # this is a child process, so we want os._exit (no clean-up necessary)
         os._exit(1)