diff --git a/lib/client/http-tracker.js b/lib/client/http-tracker.js
index c8be443..ec10cc4 100644
--- a/lib/client/http-tracker.js
+++ b/lib/client/http-tracker.js
@@ -74,7 +74,7 @@ HTTPTracker.prototype.scrape = function (opts) {
 
 HTTPTracker.prototype.destroy = function (cb) {
   var self = this
-  if (self.destroyed) return
+  if (self.destroyed) return cb && cb()
   self.destroyed = true
   clearInterval(self.interval)
 
diff --git a/lib/client/udp-tracker.js b/lib/client/udp-tracker.js
index 4bd98a5..8aec7e1 100644
--- a/lib/client/udp-tracker.js
+++ b/lib/client/udp-tracker.js
@@ -47,7 +47,7 @@ UDPTracker.prototype.scrape = function (opts) {
 
 UDPTracker.prototype.destroy = function (cb) {
   var self = this
-  if (self.destroyed) return
+  if (self.destroyed) return cb && cb()
   self.destroyed = true
   clearInterval(self.interval)
 
diff --git a/lib/client/websocket-tracker.js b/lib/client/websocket-tracker.js
index 773aa83..df73062 100644
--- a/lib/client/websocket-tracker.js
+++ b/lib/client/websocket-tracker.js
@@ -66,7 +66,7 @@ WebSocketTracker.prototype.scrape = function (opts) {
 
 WebSocketTracker.prototype.destroy = function (onclose) {
   var self = this
-  if (self.destroyed) return
+  if (self.destroyed) return onclose && onclose()
   self.destroyed = true
   clearInterval(self.interval)