diff --git a/litellm/integrations/prometheus_helpers/shared_prometheus_series_admissions.py b/litellm/integrations/prometheus_helpers/shared_prometheus_series_admissions.py
index 5898b20741a..1df27175445 100644
--- a/litellm/integrations/prometheus_helpers/shared_prometheus_series_admissions.py
+++ b/litellm/integrations/prometheus_helpers/shared_prometheus_series_admissions.py
@@ -12,8 +12,6 @@ _LABEL_VALUES: Final = TypeAdapter(tuple[str, ...])
 
 
 def _parse_admission(line: bytes) -> tuple[str, ...] | None:
-    """A line a worker could only write part of, which happens when the directory runs out of space, admits
-    nothing for every worker rather than stopping every worker from reading the lines after it."""
     try:
         return _LABEL_VALUES.validate_json(line)
     except ValidationError:
@@ -48,7 +46,7 @@ class _MetricAdmissions:
     def _append(self, label_values: tuple[str, ...]) -> None:
         descriptor: Final = os.open(self._path, os.O_WRONLY | os.O_APPEND | os.O_CREAT, 0o600)
         try:
-            os.write(descriptor, _LABEL_VALUES.dump_json(label_values) + b"\n")
+            os.write(descriptor, b"\n" + _LABEL_VALUES.dump_json(label_values) + b"\n")
         finally:
             os.close(descriptor)
 
@@ -75,7 +73,9 @@ class SharedPrometheusSeriesAdmissions:
     ``PROMETHEUS_MULTIPROC_DIR``. Each metric has one append-only file there, and its first ``max_series``
     distinct lines are the admitted label sets. Every worker reads the same lines in the same order, so all of
     them, including a worker that replaces an exited one, admit the same label sets and a scrape that merges
-    the workers stays at the cap."""
+    the workers stays at the cap. Each record sits between two newlines, so a record a worker could only write
+    part of (the directory ran out of space) is a line of its own that admits nothing for every worker, and
+    it neither hides the records after it nor runs into the next worker's record."""
 
     def __init__(self, directory: str) -> None:
         self._directory = directory
diff --git a/tests/unit/integrations/test_prometheus_series_cardinality.py b/tests/unit/integrations/test_prometheus_series_cardinality.py
index fba7ca9979b..4af0d91dfa1 100644
--- a/tests/unit/integrations/test_prometheus_series_cardinality.py
+++ b/tests/unit/integrations/test_prometheus_series_cardinality.py
@@ -1,7 +1,6 @@
 import re
 from pathlib import Path
 from threading import Thread
-from time import monotonic
 from typing import Final
 
 import pytest
@@ -56,7 +55,7 @@ def isolated_registry_and_settings(monkeypatch):
 
 @pytest.fixture
 def clock(monkeypatch):
-    now: Final = [monotonic()]
+    now: Final = [1_000.0]
     monkeypatch.setattr(bounded_prometheus_series_tracker.time, "monotonic", lambda: now[0])
     return now
 
@@ -200,9 +199,9 @@ def test_a_line_another_worker_is_still_writing_is_read_once_it_is_complete(tmp_
     assert reader.admit_series("litellm_requests_metric", ("user-b",), max_series=2)
 
 
-def test_a_line_cut_short_by_a_full_disk_admits_nothing_and_stops_no_worker(tmp_path: Path):
+def test_a_record_cut_short_by_a_full_disk_admits_nothing_and_hides_no_other_record(tmp_path: Path):
     admissions_file: Final = tmp_path / f"{PROMETHEUS_ADMITTED_SERIES_FILE_PREFIX}litellm_requests_metric"
-    admissions_file.write_bytes(b'["user-a\n')
+    admissions_file.write_bytes(b'\n["user-a')
     writer: Final = SharedPrometheusSeriesAdmissions(directory=str(tmp_path))
     reader: Final = SharedPrometheusSeriesAdmissions(directory=str(tmp_path))