diff --git a/src/sentry/monitors/models.py b/src/sentry/monitors/models.py
index 62ddc00ecd4da7..d63f189bf96348 100644
--- a/src/sentry/monitors/models.py
+++ b/src/sentry/monitors/models.py
@@ -533,9 +533,9 @@ def mark_failed(self, last_checkin=None, reason=MonitorFailure.UNKNOWN):
                 resource_id=None,
                 project_id=self.monitor.project_id,
                 event_id=uuid.uuid4().hex,
-                fingerprint=hash_from_values(
-                    ["monitor", str(self.monitor.guid), occurrence_data["reason"]]
-                ),
+                fingerprint=[
+                    hash_from_values(["monitor", str(self.monitor.guid), occurrence_data["reason"]])
+                ],
                 type=occurrence_data["group_type"],
                 issue_title=f"Monitor failure: {self.monitor.name}",
                 subtitle="",
diff --git a/tests/sentry/monitors/test_models.py b/tests/sentry/monitors/test_models.py
index f78213e7571407..f440a8a0e92eb7 100644
--- a/tests/sentry/monitors/test_models.py
+++ b/tests/sentry/monitors/test_models.py
@@ -324,7 +324,7 @@ def test_mark_failed_default_params_issue_platform(self, mock_produce_occurrence
             occurrence,
             **{
                 "project_id": self.project.id,
-                "fingerprint": hash_from_values(["monitor", str(monitor.guid), "error"]),
+                "fingerprint": [hash_from_values(["monitor", str(monitor.guid), "error"])],
                 "issue_title": f"Monitor failure: {monitor.name}",
                 "subtitle": "",
                 "resource_id": None,
@@ -393,7 +393,7 @@ def test_mark_failed_with_reason_issue_platform(self, mock_produce_occurrence_to
             occurrence,
             **{
                 "project_id": self.project.id,
-                "fingerprint": hash_from_values(["monitor", str(monitor.guid), "duration"]),
+                "fingerprint": [hash_from_values(["monitor", str(monitor.guid), "duration"])],
                 "issue_title": f"Monitor failure: {monitor.name}",
                 "subtitle": "",
                 "resource_id": None,
@@ -466,7 +466,7 @@ def test_mark_failed_with_missed_reason_issue_platform(self, mock_produce_occurr
             occurrence,
             **{
                 "project_id": self.project.id,
-                "fingerprint": hash_from_values(["monitor", str(monitor.guid), "missed_checkin"]),
+                "fingerprint": [hash_from_values(["monitor", str(monitor.guid), "missed_checkin"])],
                 "issue_title": f"Monitor failure: {monitor.name}",
                 "subtitle": "",
                 "resource_id": None,