diff --git a/tests/integration/observability/conftest.py b/tests/integration/observability/conftest.py
index c5150877857..fcac8eaba3c 100644
--- a/tests/integration/observability/conftest.py
+++ b/tests/integration/observability/conftest.py
@@ -8,8 +8,9 @@ from urllib.parse import urlparse
 
 import pytest
 import yaml
+from integration._support.client import eventually
 from integration._support.otlp_sink import SpanSinks, owned_sinks
-from integration._support.prometheus_series import CapRig, series_cap_rig
+from integration._support.prometheus_series import CapRig, series_cap_rig, spend_rows
 from pydantic import JsonValue
 
 AuditConfigWriter = Callable[[Path, Mapping[str, JsonValue]], Path]
@@ -63,4 +64,9 @@ def capped(tmp_path_factory: pytest.TempPathFactory) -> Iterator[CapRig]:
         workers=2,
         warm_keys=3,
     ) as rig:
+        eventually(
+            lambda: tuple(len(spend_rows(key.alias)) for key in rig.warm),
+            lambda counts: all(count == 1 for count in counts),
+            seconds=70,
+        )
         yield rig
diff --git a/tests/integration/observability/test_cache_hit_guardrail_metrics_chaos.py b/tests/integration/observability/test_cache_hit_guardrail_metrics_chaos.py
index c77b8eebe33..7e3b479e5f0 100644
--- a/tests/integration/observability/test_cache_hit_guardrail_metrics_chaos.py
+++ b/tests/integration/observability/test_cache_hit_guardrail_metrics_chaos.py
@@ -263,7 +263,7 @@ def test_worker_kill_mid_burst_keeps_counting(gateway: Gateway, tmp_path: Path)
 
 
 def test_proxy_restart_mid_burst_keeps_counting(gateway: Gateway, tmp_path: Path) -> None:
-    """X4: restart the owned proxy between the two halves; pre-restart count asserted, then recounted."""
+    """X4: the boot wipes the kept directory, so the second proxy counts only the second half."""
     marker: Final = uuid.uuid4().hex
     prom_dir: Final = tmp_path / "prom"
     prom_dir.mkdir()
@@ -321,8 +321,8 @@ def test_proxy_restart_mid_burst_keeps_counting(gateway: Gateway, tmp_path: Path
                     _populated(_samples(owned_two.gateway, (model,)), deployment),
                     _blank(_samples(owned_two.gateway, (model,))),
                 ),
-                lambda observed: observed[0] == len(named) and observed[1] == 0,
+                lambda observed: observed[0] == len(second_half) and observed[1] == 0,
                 seconds=70,
             )
-            assert post[0] == len(named), (pre, post, outcomes_two)
+            assert post[0] == len(second_half), (pre, post, outcomes_two)
             owned_two.gateway.post("/model/delete", {"id": deployment})