diff --git a/lib/bcoin/timedata.js b/lib/bcoin/timedata.js
index f173d660..785bcf33 100644
--- a/lib/bcoin/timedata.js
+++ b/lib/bcoin/timedata.js
@@ -56,7 +56,7 @@ TimeData.prototype.add = function add(host, time) {
   if (this.samples.length >= this.limit)
     return;
 
-  if (this.known[host])
+  if (this.known[host] != null)
     return;
 
   this.known[host] = sample;