diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc07dc19d1..10bd6539eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,11 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
 
+## 5.2.1
+
+ * **Bug Fix**
+  * Fix regression in `node/register` that caused `node_modules` to not be ignored.
+
 ## 5.2.0
 
  * **Bug Fix**
@@ -26,6 +31,7 @@ See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
   * When inferring function names that collide with upper bindings, instead of doing the wrapper, instead rename them.
   * Consider constant-like variable declaration functions to always refer to themselves so TOC can be performed.
   * Process globs manually when using `$ babel` as some shells such as Windows don't explode them. Thanks [@jden](https://github.com/jden)!
+  * Add alternative way to execute plugins via a closure that's called with the current Babel instance.
  * **Internal**
   * Remove multiple internal transformers in favor of directly doing things when we need to. Previously, declarations such as `_ref` that we needed to create in specific scopes were done at the very end via the `_declarations` transformer. Now, they're done and added to the scope **right** when they're needed. This gets rid of the crappy `_declarations` property on scope nodes and fixes the crappy regenerator bug where it was creating a new `BlockStatement` so the declarations were being lost.
   * Rework transformer traversal optimisation. Turns out that calling a `check` function for **every single node** in the AST is ridiculously expensive. 300,000 nodes timesed by ~30 transformers meant that it took tens of seconds to perform while it's quicker to just do the unnecessary traversal. Seems obvious in hindsight.
diff --git a/src/babel/api/register/node.js b/src/babel/api/register/node.js
index 9db48f13d8..3f375c5a93 100644
--- a/src/babel/api/register/node.js
+++ b/src/babel/api/register/node.js
@@ -31,8 +31,10 @@ var cache = registerCache.get();
 //
 
 var transformOpts = {};
-var ignoreRegex   = /node_modules/;
-var onlyRegex;
+
+var ignore;
+var only;
+
 var oldHandlers   = {};
 var maps          = {};
 
@@ -76,7 +78,11 @@ var compile = function (filename) {
 };
 
 var shouldIgnore = function (filename) {
-  return util.shouldIgnore(filename, ignoreRegex || [], onlyRegex || []);
+  if (!ignore && !only) {
+    return /node_modules/.test(filename);
+  } else {
+    return util.shouldIgnore(filename, ignore || [], only || []);
+  }
 };
 
 var istanbulMonkey = {};
@@ -142,8 +148,8 @@ var hookExtensions = function (_exts) {
 hookExtensions(util.canCompile.EXTENSIONS);
 
 export default function (opts = {}) {
-  if (opts.only != null) onlyRegex = util.arrayify(opts.only, util.regexify);
-  if (opts.ignore != null) ignoreRegex = util.arrayify(opts.ignore, util.regexify);
+  if (opts.only != null) only = util.arrayify(opts.only, util.regexify);
+  if (opts.ignore != null) ignore = util.arrayify(opts.ignore, util.regexify);
 
   if (opts.extensions) hookExtensions(util.arrayify(opts.extensions));