diff --git a/src/app/api/internal/revalidate-aggregate/route.ts b/src/app/api/internal/revalidate-aggregate/route.ts
index 39d221d94..0fdde6a41 100644
--- a/src/app/api/internal/revalidate-aggregate/route.ts
+++ b/src/app/api/internal/revalidate-aggregate/route.ts
@@ -44,5 +44,10 @@ export async function POST(req: Request): Promise<NextResponse> {
   // worker publish.
   revalidateTag("benchmarks", "default");
   revalidateTag("data-api-cohort", "default");
-  return NextResponse.json({ revalidated: true, tags: ["bench-aggregate", "benchmarks", "data-api-cohort"] });
+  // Invalidate HL cohort caches (builder stats, history blob, leaderboard)
+  // so new builders added to Prometheus (e.g. fomo) surface on the next
+  // request without waiting for the 1h unstable_cache TTL to expire.
+  revalidateTag("hl-cohort", "default");
+  revalidateTag("hl-history", "default");
+  return NextResponse.json({ revalidated: true, tags: ["bench-aggregate", "benchmarks", "data-api-cohort", "hl-cohort", "hl-history"] });
 }