diff --git a/README.md b/README.md
index 435601d..fe48ca9 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,10 @@ Inspired by Yan Cui's articles on latency injection for AWS Lambda (https://hack
 
 ## Changelog
 
+### 2020-10-26 v0.4.1
+
+* Made AppConfig Lambda extension port configurable using environment variable.
+
 ### 2020-10-25 v0.4.0
 
 * Added optional support for AWS AppConfig, allowing to validate failure configuration, deploy configuration using gradual or non-gradual deploy strategy, monitor deployed configuration with automatical rollback if CloudWatch Alarms is configured, and caching of configuration.
diff --git a/lib/failure.js b/lib/failure.js
index c5eda90..e5db42e 100644
--- a/lib/failure.js
+++ b/lib/failure.js
@@ -11,7 +11,12 @@ async function getConfig () {
   }
   if (process.env.FAILURE_APPCONFIG_CONFIGURATION) {
     try {
-      const url = 'http://localhost:2772/applications/' + process.env.FAILURE_APPCONFIG_APPLICATION + '/environments/' + process.env.FAILURE_APPCONFIG_ENVIRONMENT + '/configurations/' + process.env.FAILURE_APPCONFIG_CONFIGURATION
+      if (process.env.AWS_APPCONFIG_EXTENSION_HTTP_PORT) {
+        var appconfigPort = process.env.AWS_APPCONFIG_EXTENSION_HTTP_PORT
+      } else {
+        var appconfigPort = 2772
+      }
+      const url = 'http://localhost:' + appconfigPort + '/applications/' + process.env.FAILURE_APPCONFIG_APPLICATION + '/environments/' + process.env.FAILURE_APPCONFIG_ENVIRONMENT + '/configurations/' + process.env.FAILURE_APPCONFIG_CONFIGURATION
       const response = await fetch(url)
       const json = await response.json()
       return json
@@ -38,8 +43,6 @@ async function getConfig () {
 var injectFailure = function (fn) {
   return async function () {
     try {
-      // let configResponse = await getConfig()
-      // let config = JSON.parse(configResponse)
       let config = await getConfig()
       if (config.isEnabled === true && Math.random() < config.rate) {
         if (config.failureMode === 'latency') {
diff --git a/package-lock.json b/package-lock.json
index 5b8b1d5..05d47e4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "failure-lambda",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 632a0e7..06c4818 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "failure-lambda",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "Module for failure injection into AWS Lambda",
   "main": "./lib/failure.js",
   "scripts": {