diff --git a/README.md b/README.md
index d182ed913d..616e3af3ff 100644
--- a/README.md
+++ b/README.md
@@ -192,21 +192,26 @@ require("6to5/register");
 ```
 
 **NOTE:** By default all requires to `node_modules` will be ignored. You can
-override this by passing an ignore regex via:
+override this by passing an ignore regex with`.
 
-```javascript
-require("6to5/register")(/regex/);
-```
-
-You can also customise the file extensions that the require hook will use via:
+##### Options
 
 ```javascript
 require("6to5/register")({
-  // optional ignore regex
-  ignoreRegex: /regex/,
+  // Optional ignore regex - if any filenames **do** match this regex then they
+  // aren't compiled
+  ignore: /regex/,
 
-  // this will remove the currently hooked extensions of .es6 and .js so you'll
-  // have to add them back if you want them to be used again
+  // Optional only regex - if any filenames **don't** match this regex then they
+  // aren't compiled
+  only: /my_es6_folder/,
+
+  // See options above for usage
+  whitelist: [],
+  blacklist: [],
+
+  // This will remove the currently hooked extensions of .es6 and .js so you'll
+  // have to add them back if you want them to be used again.
   extensions: [".js", ".es6"]
 });
 ```
diff --git a/lib/6to5/register.js b/lib/6to5/register.js
index 69f68322c0..40dabc000a 100644
--- a/lib/6to5/register.js
+++ b/lib/6to5/register.js
@@ -24,7 +24,11 @@ var blacklist  = [];
 
 var blacklistTest = function (transformer, code) {
   try {
-    new Function(code);
+    if (_.isFunction(code)) {
+      code();
+    } else {
+      new Function(code);
+    }
     blacklist.push(transformer);
   } catch (err) {
     if (err.name !== "SyntaxError") throw err;
@@ -34,34 +38,37 @@ var blacklistTest = function (transformer, code) {
 blacklistTest("arrayComprehension", "var foo = [for (foo of bar) foo * foo];");
 blacklistTest("arrowFunctions", "var foo = x => x * x;");
 blacklistTest("classes", "class Foo {}");
-//blacklistTest("computedPropertyNames", "");
-blacklistTest("constants", "const foo = 0;");
+blacklistTest("computedPropertyNames", "var foo = { [foo]: bar };");
+//blacklistTest("constants", "const foo = 0;");
 blacklistTest("defaultParamaters", "var foo = function (bar = 0) {};");
 blacklistTest("destructuring", "var { x, y } = { x: 0, y: 0 };");
 blacklistTest("forOf", "for (var foo of bar) {}");
 blacklistTest("generators", "function* foo() {}");
 blacklistTest("letScoping", "let foo = 0;");
-//blacklistTest("modules", "");
-//blacklistTest("propertyMethodAssignment", "");
+blacklistTest("modules", 'import foo from "from";');
+blacklistTest("propertyMethodAssignment", "{ get foo() {} }");
 blacklistTest("propertyNameShorthand", "var foo = { x, y };");
-//blacklistTest("restParameters", "");
-//blacklistTest("spread", "");
+blacklistTest("restParameters", "function foo(...bar) {}");
+blacklistTest("spread", "foo(...bar);");
 blacklistTest("templateLiterals", "`foo`");
-blacklistTest("unicodeRegex", "/foo/u");
+blacklistTest("unicodeRegex", function () { new RegExp("foo", "u"); });
 
 //
 
 var ignoreRegex = /node_modules/;
+var onlyRegex;
+var whitelist   = [];
 var exts        = {};
 var maps        = {};
 var old         = require.extensions[".js"];
 
 var loader = function (m, filename) {
-  if (ignoreRegex && ignoreRegex.test(filename)) {
+  if ((ignoreRegex && ignoreRegex.test(filename)) || (onlyRegex && !onlyRegex.test(filename))) {
     return old.apply(this, arguments);
   }
 
   var result = to5.transformFileSync(filename, {
+    whitelist: whitelist,
     blacklist: blacklist,
     sourceMap: true
   });
@@ -87,12 +94,16 @@ var hookExtensions = function (_exts) {
 hookExtensions([".es6", ".js"]);
 
 module.exports = function (opts) {
+  // normalise options
   opts = opts || {};
-  if (_.isRegExp(opts)) opts = { ignoreRegex: opts };
+  if (_.isRegExp(opts)) opts = { ignore: opts };
+  opts.ignore = opts.ignore || opts.ignoreRegex;
 
-  if (opts.ignoreRegex != null) ignoreRegex = opts.ignoreRegex;
+  if (opts.only != null) onlyRegex = opts.only;
+  if (opts.ignore != null) ignoreRegex = opts.ignore;
 
   if (opts.extensions) hookExtensions(opts.extensions);
 
   if (opts.blacklist) blacklist = opts.blacklist;
+  if (opts.whitelist) whitelist = opts.whitelist;
 };