diff --git a/src/eventStorePersistentSubscriptionBase.js b/src/eventStorePersistentSubscriptionBase.js
index 90eb6b5..9d09eb1 100644
--- a/src/eventStorePersistentSubscriptionBase.js
+++ b/src/eventStorePersistentSubscriptionBase.js
@@ -38,7 +38,7 @@ EventStorePersistentSubscriptionBase.prototype.start = function() {
   return this._startSubscription(this._subscriptionId, this._streamId, this._bufferSize, this._userCredentials,
                           this._onEventAppeared.bind(this), this._onSubscriptionDropped.bind(this), this._settings)
       .then(function(subscription) {
-        this._log.debug('Subscription started.');
+        self._log.debug('Subscription started.');
         self._subscription = subscription;
         return self;
       });