diff --git a/src/sentry/monitors/models.py b/src/sentry/monitors/models.py
index ab74d6378294..c6cadd13fe39 100644
--- a/src/sentry/monitors/models.py
+++ b/src/sentry/monitors/models.py
@@ -4,7 +4,7 @@
 import uuid
 import zoneinfo
 from collections.abc import Sequence
-from datetime import datetime
+from datetime import UTC, datetime
 from functools import cache
 from typing import TYPE_CHECKING, ClassVar, Self, override
 from uuid import uuid4
@@ -353,7 +353,8 @@ def get_next_expected_checkin_latest(self, last_checkin: datetime) -> datetime:
         """
         from sentry.monitors.utils import get_checkin_margin
 
-        next_checkin = self.get_next_expected_checkin(last_checkin)
+        # Add the margin in UTC: local wall-clock arithmetic drops the DST fold
+        next_checkin = self.get_next_expected_checkin(last_checkin).astimezone(UTC)
         return next_checkin + get_checkin_margin(self.config.get("checkin_margin"))
 
     def update_config(self, config_payload, validated_config):
diff --git a/tests/sentry/monitors/test_models.py b/tests/sentry/monitors/test_models.py
index 6d2c52c81bfd..ef3026dc1524 100644
--- a/tests/sentry/monitors/test_models.py
+++ b/tests/sentry/monitors/test_models.py
@@ -71,6 +71,28 @@ def test_next_run_latest_crontab_with_margin(self) -> None:
             2019, 1, 1, 1, 16, tzinfo=timezone.utc
         )
 
+    def test_next_run_latest_crontab_during_dst_fold(self) -> None:
+        # Europe/Berlin repeats 02:00-02:59 local time on 2024-10-27 from 01:00 UTC
+        ts = datetime(2024, 10, 27, 1, 0, 3, tzinfo=timezone.utc)
+        monitor = Monitor(
+            config={
+                "schedule_type": ScheduleType.CRONTAB,
+                "schedule": "* * * * *",
+                "timezone": "Europe/Berlin",
+                "checkin_margin": 5,
+                "max_runtime": None,
+            }
+        )
+        monitor_environment = MonitorEnvironment(monitor=monitor, last_checkin=ts)
+
+        # PEP 495: inter-zone == is always False for a time with fold=1
+        assert monitor_environment.monitor.get_next_expected_checkin(ts).astimezone(
+            timezone.utc
+        ) == datetime(2024, 10, 27, 1, 1, tzinfo=timezone.utc)
+        assert monitor_environment.monitor.get_next_expected_checkin_latest(ts) == datetime(
+            2024, 10, 27, 1, 6, tzinfo=timezone.utc
+        )
+
     def test_next_run_crontab_with_timezone(self) -> None:
         ts = datetime(2019, 1, 1, 1, 10, 20, tzinfo=timezone.utc)
         monitor = Monitor(