diff --git a/tests/test_services_retrieval_telemetry.py b/tests/test_services_retrieval_telemetry.py
index 709840f..8605e39 100644
--- a/tests/test_services_retrieval_telemetry.py
+++ b/tests/test_services_retrieval_telemetry.py
@@ -706,11 +706,19 @@ async def test_coverage_is_per_source_because_the_table_is_older_than_its_arms(
     UID = 990077
     now = datetime.now(timezone.utc)
     async with async_session() as s:
-        # An old surface, recording since well before any window we ask for.
+        # An old surface, recording since well before any window we ask for,
+        # AND still recording inside it. Both rows are needed: `complete_from`
+        # comes from the all-time query, but a source only gets a bucket at all
+        # if it has rows in the window, so the 90-day row alone would leave
+        # nothing to assert on.
         s.add(RetrievalLog(
             user_id=UID, source="auto_inject", result_count=1,
             created_at=now - timedelta(days=90),
         ))
+        s.add(RetrievalLog(
+            user_id=UID, source="auto_inject", result_count=1,
+            created_at=now - timedelta(days=1),
+        ))
         # A young arm, first written INSIDE the window below.
         s.add(RetrievalLog(
             user_id=UID, source="pre_tool_rule", result_count=1,