diff --git a/CHANGELOG.md b/CHANGELOG.md
index bacd23acc1..9ddbff4584 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fix unicode characters not rendering correctly in webhooks @mderynck ([#3670](https://github.com/grafana/oncall/pull/3670))
+- Fix internal schedule detail API to set oncall_now for a schedule in orgs with multiple entries ([#3671](https://github.com/grafana/oncall/pull/3671))
 
 ## v1.3.85 (2024-01-12)
 
diff --git a/engine/apps/api/tests/test_schedules.py b/engine/apps/api/tests/test_schedules.py
index a33ea55995..839f6e5801 100644
--- a/engine/apps/api/tests/test_schedules.py
+++ b/engine/apps/api/tests/test_schedules.py
@@ -565,6 +565,69 @@ def test_get_detail_web_schedule(
     assert response.data == expected_payload
 
 
+@pytest.mark.django_db
+def test_get_detail_schedule_oncall_now_multipage_objects(
+    make_organization_and_user_with_plugin_token, make_schedule, make_on_call_shift, make_user_auth_headers
+):
+    organization, user, token = make_organization_and_user_with_plugin_token()
+    # make sure our schedule would be in the second page of the listing page
+    for i in range(16):
+        make_schedule(organization, schedule_class=OnCallScheduleWeb, name=f"schedule {i}")
+
+    schedule = make_schedule(
+        organization,
+        schedule_class=OnCallScheduleWeb,
+        name="test_web_schedule",
+    )
+    now = timezone.now().replace(hour=0, minute=0, second=0, microsecond=0)
+    start_date = now - timezone.timedelta(days=7)
+    data = {
+        "start": start_date,
+        "rotation_start": start_date,
+        "duration": timezone.timedelta(seconds=86400),
+        "priority_level": 1,
+        "frequency": CustomOnCallShift.FREQUENCY_DAILY,
+        "schedule": schedule,
+    }
+    on_call_shift = make_on_call_shift(
+        organization=organization, shift_type=CustomOnCallShift.TYPE_ROLLING_USERS_EVENT, **data
+    )
+    on_call_shift.add_rolling_users([[user]])
+
+    client = APIClient()
+    url = reverse("api-internal:schedule-detail", kwargs={"pk": schedule.public_primary_key})
+
+    expected_payload = {
+        "id": schedule.public_primary_key,
+        "team": None,
+        "name": "test_web_schedule",
+        "type": 2,
+        "time_zone": "UTC",
+        "slack_channel": None,
+        "user_group": None,
+        "warnings": [],
+        "on_call_now": [
+            {
+                "pk": user.public_primary_key,
+                "username": user.username,
+                "avatar": user.avatar_url,
+                "avatar_full": user.avatar_full_url,
+            }
+        ],
+        "has_gaps": False,
+        "mention_oncall_next": False,
+        "mention_oncall_start": True,
+        "notify_empty_oncall": 0,
+        "notify_oncall_shift_freq": 1,
+        "number_of_escalation_chains": 0,
+        "enable_web_overrides": True,
+    }
+
+    response = client.get(url, format="json", **make_user_auth_headers(user, token))
+    assert response.status_code == status.HTTP_200_OK
+    assert response.data == expected_payload
+
+
 @pytest.mark.django_db
 def test_create_calendar_schedule(schedule_internal_api_setup, make_user_auth_headers):
     user, token, _, _, _, _ = schedule_internal_api_setup
diff --git a/engine/apps/api/views/schedule.py b/engine/apps/api/views/schedule.py
index 74908fe5f8..16047ec5a1 100644
--- a/engine/apps/api/views/schedule.py
+++ b/engine/apps/api/views/schedule.py
@@ -137,8 +137,14 @@ def oncall_users(self):
         The result of this method is cached and is reused for the whole lifetime of a request,
         since self.get_serializer_context() is called multiple times for every instance in the queryset.
         """
-        current_page_schedules = self.paginate_queryset(self.filter_queryset(self.get_queryset(annotate=False)))
-        return get_oncall_users_for_multiple_schedules(current_page_schedules)
+        current_schedules = self.get_queryset(annotate=False).none()
+        if self.action == "list":
+            # listing page, only get oncall users for current page schedules
+            current_schedules = self.paginate_queryset(self.filter_queryset(self.get_queryset(annotate=False)))
+        elif self.kwargs.get("pk"):
+            # if this is a particular schedule detail, only consider it as current
+            current_schedules = [self.get_object(annotate=False)]
+        return get_oncall_users_for_multiple_schedules(current_schedules)
 
     def get_serializer_context(self):
         context = super().get_serializer_context()