diff --git a/index.d.ts b/index.d.ts
index 7bb196d8..15d4e269 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -555,6 +555,7 @@ export interface SummaryConfiguration<T extends string>
 	percentiles?: number[];
 	maxAgeSeconds?: number;
 	ageBuckets?: number;
+	pruneAgedBuckets?: boolean;
 	compressCount?: number;
 	collect?: CollectFunction<Summary<T>>;
 }