diff --git a/CHANGELOG.md b/CHANGELOG.md
index d9d5d31..4200f20 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All notable changes to the LaunchDarkly Node.js SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [4.0.3] - 2018-03-27
+### Fixed
+- Fixed a [bug](https://github.com/launchdarkly/node-client/issues/85) that would cause an unhandled promise rejection warning-- and, depending on your Node configuration, a crash-- if there was an HTTP error during an automatic event flush.
+
 ## [4.0.2] - 2018-03-14
 ### Fixed
 - In the Redis feature store, fixed synchronization problems that could cause a feature flag update to be missed if several of them happened in rapid succession.
diff --git a/index.js b/index.js
index a470053..95ef832 100644
--- a/index.js
+++ b/index.js
@@ -39,7 +39,8 @@ var new_client = function(sdk_key, config) {
       queue = [],
       requestor,
       update_processor,
-      event_queue_shutdown = false;
+      event_queue_shutdown = false,
+      flush_timer;
 
   config = Object.assign({}, config || {});
   config.user_agent = 'NodeJSClient/' + package_json.version;
@@ -241,6 +242,7 @@ var new_client = function(sdk_key, config) {
       update_processor.close();
     }
     config.feature_store.close();
+    clearInterval(flush_timer);
   }
 
   client.is_offline = function() {
@@ -334,8 +336,11 @@ var new_client = function(sdk_key, config) {
     enqueue(event);
   }
 
-  // TODO keep the reference and stop flushing after close
-  setInterval(client.flush.bind(client), config.flush_interval * 1000).unref();
+  function background_flush() {
+    client.flush().then(function() {}, function() {});
+  }
+
+  flush_timer = setInterval(background_flush, config.flush_interval * 1000);
 
   return client;
 };
diff --git a/package.json b/package.json
index 9bee3fe..686e561 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ldclient-node",
-  "version": "4.0.2",
+  "version": "4.0.3",
   "description": "LaunchDarkly SDK for Node.js",
   "main": "index.js",
   "scripts": {