diff --git a/index.js b/index.js
index 1e02911..a33b37e 100644
--- a/index.js
+++ b/index.js
@@ -6,7 +6,7 @@ const BATCH_BYTES = 2048;
 // SNAPSHOT_MIN_MS is no longer needed as we removed throttled saving.
 
 // Heartbeat configuration: run every 4s while streaming to prevent eviction.
-const HB_INTERVAL_MS = 4000;
+const HB_INTERVAL_MS = 3000;
 const MAX_RUN_MS = 15 * 60 * 1000;
 
 const CORS_HEADERS = {