diff --git a/plugins/traefik/routes.py b/plugins/traefik/routes.py
index 92520f4..120dbda 100644
--- a/plugins/traefik/routes.py
+++ b/plugins/traefik/routes.py
@@ -3,7 +3,7 @@ from __future__ import annotations
 from collections import defaultdict
 from datetime import datetime, timedelta, timezone
 from quart import Blueprint, current_app, render_template, request
-from sqlalchemy import Integer, cast, func, select, text
+from sqlalchemy import func, select, text
 import json
 
 from steward.auth.middleware import require_role
@@ -186,9 +186,7 @@ async def rows():
         routers = sorted(newest)
 
         b_secs = bucket_seconds(since)
-        bucket_col = (
-            cast(func.extract('epoch', TraefikMetric.scraped_at), Integer) / b_secs
-        ).label("bucket")
+        bucket_col = _time_bucket(TraefikMetric.scraped_at, b_secs)
 
         router_data = []
         for router in routers:
@@ -375,6 +373,15 @@ async def widget_access_log():
                                  summary=summary, widget_id=widget_id)
 
 
+def _time_bucket(column, seconds: int):
+    """The start of the `seconds`-wide window a timestamp falls in, as
+    host_agent/metrics_query.py buckets. Integer epoch / int rendered as
+    numeric division (no two scrapes shared a bucket) and overflowed int4
+    after 2038 (#5256)."""
+    return func.date_bin(func.make_interval(0, 0, 0, 0, 0, 0, int(seconds)), column,
+                         func.to_timestamp(0)).label("bucket")
+
+
 async def request_history(db, since, bucket_seconds: int) -> list[dict]:
     """[{"at", "req_rate", "err_pct"}] per time bucket since `since`: each
     scrape summed over routers (the total req/s), averaged over the bucket;
@@ -390,7 +397,7 @@ async def request_history(db, since, bucket_seconds: int) -> list[dict]:
         .group_by(TraefikMetric.scraped_at)
         .subquery()
     )
-    bucket_col = (cast(func.extract("epoch", per_scrape.c.at), Integer) / bucket_seconds).label("bucket")
+    bucket_col = _time_bucket(per_scrape.c.at, bucket_seconds)
     rows = (await db.execute(
         select(
             func.avg(per_scrape.c.req).label("req_rate"),
diff --git a/tests/integration/test_traefik_latest.py b/tests/integration/test_traefik_latest.py
index 916a7b2..9ed2a0a 100644
--- a/tests/integration/test_traefik_latest.py
+++ b/tests/integration/test_traefik_latest.py
@@ -48,24 +48,29 @@ def test_each_router_reads_as_its_newest_row(app):
 
 def test_the_request_chart_sums_routers_and_weights_the_5xx_share(app):
     """#5256: two routers in one scrape are 4 req/s in total, not an average
-    of 2; a 5xx share of 50% on the 3 req/s router is 37.5% of all traffic."""
+    of 2; a 5xx share of 50% on the 3 req/s router is 37.5% of that scrape's
+    traffic. A second scrape 30 s later shares the minute's bucket, so the
+    bucket averages the two totals and weights the share over both."""
     from plugins.traefik.models import TraefikMetric
     from plugins.traefik.routes import request_history
 
     # Far ahead of every other test's rows, so only these fall in the window.
     at = datetime(2099, 1, 1, 12, 0, tzinfo=timezone.utc) + timedelta(minutes=uuid.uuid4().int % 10_000)
 
-    def row(name, rate, e5):
-        return TraefikMetric(router_name=name, scraped_at=at, request_rate=rate, error_rate_4xx_pct=0.0,
+    def row(name, rate, e5, when=None):
+        return TraefikMetric(router_name=name, scraped_at=when or at, request_rate=rate, error_rate_4xx_pct=0.0,
                              error_rate_5xx_pct=e5, latency_p50_ms=1.0, latency_p95_ms=2.0,
                              latency_p99_ms=3.0, response_bytes_rate=0.0)
 
     async def go():
         async with app.db_sessionmaker() as s:
             async with s.begin():
-                s.add_all([row("quiet@docker", 1.0, 0.0), row("busy@docker", 3.0, 50.0)])
+                later = at + timedelta(seconds=30)
+                s.add_all([row("quiet@docker", 1.0, 0.0), row("busy@docker", 3.0, 50.0),
+                           row("quiet@docker", 2.0, 0.0, later), row("busy@docker", 4.0, 0.0, later)])
             async with s.begin():
                 return await request_history(s, at, 60)
 
     got = asyncio.run(go())
-    assert got == [{"at": at, "req_rate": 4.0, "err_pct": 37.5}]
+    # One bucket: totals 4 and 6 average to 5; 150 weighted 5xx over 10 req/s is 15%.
+    assert got == [{"at": at, "req_rate": 5.0, "err_pct": 15.0}]