diff --git a/parseCommandLine.js b/parseCommandLine.js
index 65061e3f..17a2d8af 100644
--- a/parseCommandLine.js
+++ b/parseCommandLine.js
@@ -24,12 +24,21 @@ function parseCommandLine(config) {
   // optimist default API requires you to write the command name three time
   // This is a small wrapper to accept an object instead
   for (var i = 0; i < config.length; ++i) {
+    if (config[i].type === 'string') {
+      optimist.string(config[i].command);
+    } else {
+      optimist.boolean(config[i].command);
+    }
+
     optimist
-      .boolean(config[i].command)
       .default(config[i].command, config[i].default)
       .describe(config[i].command, config[i].description);
+
+    if (config[i].required) {
+      optimist.demand(config[i].command);
+    }
   }
-  var argv = optimist.argv;
+  var argv = optimist.parse(process.argv);
 
   // optimist doesn't have support for --dev=false, instead it returns 'false'
   for (var i = 0; i < config.length; ++i) {