diff --git a/README.md b/README.md
index f558e99..b026052 100644
--- a/README.md
+++ b/README.md
@@ -47,6 +47,9 @@ $ npx aws-api-gateway-cli-test --options
 
 This command takes the following options:
 
+- `config`
+  Read parameters from a file.  File must be valid JSON and end in a .json extension.  Command line parameters will override the same config file parameter.
+
 - `username`
   The username of the Cognito User Pool user.
 
diff --git a/index.js b/index.js
index 234fde8..c7bb4ed 100755
--- a/index.js
+++ b/index.js
@@ -14,6 +14,7 @@ global.navigator = function() {
 };
 
 var argv = require("yargs")
+  .config()
   .option("username", {
     describe: "Username of the user",
     demandOption: true,