diff --git a/.travis.yml b/.travis.yml
index 13b71c9..aca7a0f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,6 @@ dist: trusty
 
 language: node_js
 node_js:
-  - "6"
   - "8"
   - "10"
   - "12"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fda5cce..156df89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,13 @@
 # Changelog
-## 9.0.0 - Pending
-- ***BREAKING***: Dropping support for node v4
-- **Change**: Updated dev dependencies `sinon` and `nyc`
+## 9.0.0
+- ***BREAKING***: Converted project to Typescript
+- ***BREAKING***: Changes to all option flags, see docs for new options
+- ***BREAKING***: Dropping support for node v4 and v6
+- **Change**: Updated all dependencies
 - **Change**: Update package-lock.json file
-- **Addition**: Added node v10 to build automation
+- **Feature**: Added support for asyncronous .env and .rc files
+- 
+- **Change**: Added node v10 and v12 to build automation
 
 ## 8.0.2
 - **Change**: Updated dependencies and packages.json to fix `npm audit` concerns.
diff --git a/package-lock.json b/package-lock.json
index dfcd6b3..a6fc911 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -180,12 +180,6 @@
       "integrity": "sha512-6ee09Ugx6GyEr0opUIakmxIWFNmqYPjkqa3/BuxCBokA0klsOLPgMD5K4q40lH7/yZVuJVzOfQpd7pipwjngkQ==",
       "dev": true
     },
-    "@types/util.promisify": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/@types/util.promisify/-/util.promisify-1.0.0.tgz",
-      "integrity": "sha512-JK7Ecs9ETHfYSoG5ZILe30Ar9fmMT7vZTirfZQQ9OAZDB8TfPVV6aQkYPtfx2MFfB+yrSY4jCfrvMdemv/9VHw==",
-      "dev": true
-    },
     "@typescript-eslint/eslint-plugin": {
       "version": "1.7.0",
       "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-1.7.0.tgz",
@@ -668,6 +662,7 @@
       "version": "1.1.3",
       "resolved": "https://registry.npmjs.org/define-properties/-/define-properties-1.1.3.tgz",
       "integrity": "sha512-3MqfYKj2lLzdMSf8ZIZE/V+Zuy+BgD6f164e8K2w7dgnpKArBDerGYpM46IYYcjnkdPNMjPk9A6VFB8+3SKlXQ==",
+      "dev": true,
       "requires": {
         "object-keys": "^1.0.12"
       }
@@ -731,6 +726,7 @@
       "version": "1.13.0",
       "resolved": "https://registry.npmjs.org/es-abstract/-/es-abstract-1.13.0.tgz",
       "integrity": "sha512-vDZfg/ykNxQVwup/8E1BZhVzFfBxs9NqMzGcvIJrqg5k2/5Za2bWo40dK2J1pgLngZ7c+Shh8lwYtLGyrwPutg==",
+      "dev": true,
       "requires": {
         "es-to-primitive": "^1.2.0",
         "function-bind": "^1.1.1",
@@ -744,6 +740,7 @@
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/es-to-primitive/-/es-to-primitive-1.2.0.tgz",
       "integrity": "sha512-qZryBOJjV//LaxLTV6UC//WewneB3LcXOL9NP++ozKVXsIIIpm/2c13UDiD9Jp2eThsecw9m3jPqDwTyobcdbg==",
+      "dev": true,
       "requires": {
         "is-callable": "^1.1.4",
         "is-date-object": "^1.0.1",
@@ -1262,7 +1259,8 @@
     "function-bind": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.1.tgz",
-      "integrity": "sha512-yIovAzMX49sF8Yl58fSCWJ5svSLuaibPxXQJFLmBObTuCr0Mf1KiPopGM9NiFjiYBCbfaa2Fh6breQ6ANVTI0A=="
+      "integrity": "sha512-yIovAzMX49sF8Yl58fSCWJ5svSLuaibPxXQJFLmBObTuCr0Mf1KiPopGM9NiFjiYBCbfaa2Fh6breQ6ANVTI0A==",
+      "dev": true
     },
     "functional-red-black-tree": {
       "version": "1.0.1",
@@ -1372,6 +1370,7 @@
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/has/-/has-1.0.3.tgz",
       "integrity": "sha512-f2dvO0VU6Oej7RkWJGrehjbzMAjFp5/VKPp5tTpWIV4JHHZK1/BxbFRtf/siA2SWTe09caDmVtYYzWEIbBS4zw==",
+      "dev": true,
       "requires": {
         "function-bind": "^1.1.1"
       }
@@ -1385,7 +1384,8 @@
     "has-symbols": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.0.0.tgz",
-      "integrity": "sha1-uhqPGvKg/DllD1yFA2dwQSIGO0Q="
+      "integrity": "sha1-uhqPGvKg/DllD1yFA2dwQSIGO0Q=",
+      "dev": true
     },
     "hasha": {
       "version": "3.0.0",
@@ -1525,12 +1525,14 @@
     "is-callable": {
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/is-callable/-/is-callable-1.1.4.tgz",
-      "integrity": "sha512-r5p9sxJjYnArLjObpjA4xu5EKI3CuKHkJXMhT7kwbpUyIFD1n5PMAsoPvWnvtZiNz7LjkYDRZhd7FlI0eMijEA=="
+      "integrity": "sha512-r5p9sxJjYnArLjObpjA4xu5EKI3CuKHkJXMhT7kwbpUyIFD1n5PMAsoPvWnvtZiNz7LjkYDRZhd7FlI0eMijEA==",
+      "dev": true
     },
     "is-date-object": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/is-date-object/-/is-date-object-1.0.1.tgz",
-      "integrity": "sha1-mqIOtq7rv/d/vTPnTKAbM1gdOhY="
+      "integrity": "sha1-mqIOtq7rv/d/vTPnTKAbM1gdOhY=",
+      "dev": true
     },
     "is-fullwidth-code-point": {
       "version": "2.0.0",
@@ -1548,6 +1550,7 @@
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/is-regex/-/is-regex-1.0.4.tgz",
       "integrity": "sha1-VRdIm1RwkbCTDglWVM7SXul+lJE=",
+      "dev": true,
       "requires": {
         "has": "^1.0.1"
       }
@@ -1562,6 +1565,7 @@
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/is-symbol/-/is-symbol-1.0.2.tgz",
       "integrity": "sha512-HS8bZ9ox60yCJLH9snBpIwv9pYUAkcuLhSA1oero1UB5y9aiQpRA8y2ex945AOtCZL1lJDeIk3G5LthswI46Lw==",
+      "dev": true,
       "requires": {
         "has-symbols": "^1.0.0"
       }
@@ -2275,7 +2279,8 @@
     "object-keys": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/object-keys/-/object-keys-1.1.1.tgz",
-      "integrity": "sha512-NuAESUOUMrlIXOfHKzD6bpPu3tYt3xvjNdRIQ+FeT0lNb4K8WR70CaDxhuNguS2XG+GjkyMwOzsN5ZktImfhLA=="
+      "integrity": "sha512-NuAESUOUMrlIXOfHKzD6bpPu3tYt3xvjNdRIQ+FeT0lNb4K8WR70CaDxhuNguS2XG+GjkyMwOzsN5ZktImfhLA==",
+      "dev": true
     },
     "object.assign": {
       "version": "4.1.0",
@@ -2293,6 +2298,7 @@
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/object.getownpropertydescriptors/-/object.getownpropertydescriptors-2.0.3.tgz",
       "integrity": "sha1-h1jIRvW0B62rDyNuCYbxSwUcqhY=",
+      "dev": true,
       "requires": {
         "define-properties": "^1.1.2",
         "es-abstract": "^1.5.1"
@@ -3217,15 +3223,6 @@
         "punycode": "^2.1.0"
       }
     },
-    "util.promisify": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/util.promisify/-/util.promisify-1.0.0.tgz",
-      "integrity": "sha512-i+6qA2MPhvoKLuxnJNpXAGhg7HphQOSUq2LKMZD0m15EiskXUkMvKdF4Uui0WYeCUGea+o2cw/ZuwehtfsrNkA==",
-      "requires": {
-        "define-properties": "^1.1.2",
-        "object.getownpropertydescriptors": "^2.0.3"
-      }
-    },
     "uuid": {
       "version": "3.3.2",
       "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.2.tgz",
diff --git a/package.json b/package.json
index 623bcad..6c2631b 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "Executes a command using the envs in the provided env file",
   "main": "lib/index.js",
   "engines": {
-    "node": ">=6.0.0"
+    "node": ">=8.0.0"
   },
   "bin": {
     "env-cmd": "bin/env-cmd.js"
@@ -43,8 +43,7 @@
   "homepage": "https://github.com/toddbluhm/env-cmd#readme",
   "dependencies": {
     "commander": "^2.20.0",
-    "cross-spawn": "6.0.5",
-    "util.promisify": "^1.0.0"
+    "cross-spawn": "6.0.5"
   },
   "devDependencies": {
     "@types/chai": "4.1.7",
@@ -52,7 +51,6 @@
     "@types/mocha": "5.2.6",
     "@types/node": "^12.0.0",
     "@types/sinon": "^7.0.11",
-    "@types/util.promisify": "^1.0.0",
     "@typescript-eslint/eslint-plugin": "^1.7.0",
     "@typescript-eslint/parser": "^1.7.0",
     "chai": "4.2.0",
diff --git a/src/parse-rc-file.ts b/src/parse-rc-file.ts
index 7c26a92..7bf3417 100644
--- a/src/parse-rc-file.ts
+++ b/src/parse-rc-file.ts
@@ -1,5 +1,5 @@
 import { stat, readFile } from 'fs'
-import * as promisify from 'util.promisify'
+import { promisify } from 'util'
 import { extname } from 'path'
 import { resolveEnvFilePath, isPromise } from './utils'