diff --git a/src/components/charts/health-chart/use-health-chart-series.ts b/src/components/charts/health-chart/use-health-chart-series.ts
index 7935f2f5f..03dd263ee 100644
--- a/src/components/charts/health-chart/use-health-chart-series.ts
+++ b/src/components/charts/health-chart/use-health-chart-series.ts
@@ -73,8 +73,8 @@ async function readDailySeries({
   async function fetchSleepNights() {
     const sleepParams = new URLSearchParams();
     sleepParams.set("kind", "sleep");
-    // The series route caps sleep at 365 days; clamp the request so a
-    // longer comparison window still resolves.
+    // The series route caps `days` at 3650 (the "All" tab); clamp the
+    // request so a window stretched by a comparison shift still resolves.
     sleepParams.set(
       "days",
       String(Math.max(1, Math.min(3650, Math.ceil(fetchWindow.windowDays)))),