diff --git a/src/babel/transformation/transformers/deprecated.json b/src/babel/transformation/transformers/deprecated.json
index 3677c988f5..ceb2a42800 100644
--- a/src/babel/transformation/transformers/deprecated.json
+++ b/src/babel/transformation/transformers/deprecated.json
@@ -8,5 +8,8 @@
   "utility.inlineExpressions": "minification.constantFolding",
   "utility.deadCodeElimination": "minification.deadCodeElimination",
   "utility.removeConsoleCalls": "minification.removeConsole",
-  "utility.removeDebugger": "minification.removeDebugger"
+  "utility.removeDebugger": "minification.removeDebugger",
+
+  "es6.parameters.rest": "es6.parameters",
+  "es6.parameters.default": "es6.parameters"
 }
diff --git a/src/babel/transformation/transformers/es6/destructuring.js b/src/babel/transformation/transformers/es6/destructuring.js
index d1c79fd5e0..ebf7751d7a 100644
--- a/src/babel/transformation/transformers/es6/destructuring.js
+++ b/src/babel/transformation/transformers/es6/destructuring.js
@@ -70,7 +70,15 @@ export var visitor = {
       let pattern = node.params[i];
       if (!t.isPattern(pattern)) continue;
 
-      var ref = node.params[i] = scope.generateUidIdentifier("ref");
+      var ref = scope.generateUidIdentifier("ref");
+      if (t.isAssignmentPattern(pattern)) {
+        var _pattern = pattern;
+        pattern = pattern.left;
+        _pattern.left = ref;
+      } else {
+        node.params[i] = ref;
+      }
+
       t.inherits(ref, pattern);
 
       var destructuring = new DestructuringTransformer({
diff --git a/src/babel/transformation/transformers/es6/parameters.default.js b/src/babel/transformation/transformers/es6/parameters/default.js
similarity index 92%
rename from src/babel/transformation/transformers/es6/parameters.default.js
rename to src/babel/transformation/transformers/es6/parameters/default.js
index f6cd429a2f..7e022d8811 100644
--- a/src/babel/transformation/transformers/es6/parameters.default.js
+++ b/src/babel/transformation/transformers/es6/parameters/default.js
@@ -1,7 +1,7 @@
-import callDelegate from "../../helpers/call-delegate";
-import getFunctionArity from "../../helpers/get-function-arity";
-import * as util from  "../../../util";
-import * as t from "../../../types";
+import callDelegate from "../../../helpers/call-delegate";
+import getFunctionArity from "../../../helpers/get-function-arity";
+import * as util from  "../../../../util";
+import * as t from "../../../../types";
 
 var hasDefaults = function (node) {
   for (var i = 0; i < node.params.length; i++) {
@@ -38,7 +38,7 @@ export var visitor = {
 
     //
     var argsIdentifier = t.identifier("arguments");
-    argsIdentifier._shadowedFunctionLiteral = true;
+    argsIdentifier._shadowedFunctionLiteral = node;
 
     // push a default parameter definition
     function pushDefNode(left, right, i) {
diff --git a/src/babel/transformation/transformers/es6/parameters/index.js b/src/babel/transformation/transformers/es6/parameters/index.js
new file mode 100644
index 0000000000..a18bc96c28
--- /dev/null
+++ b/src/babel/transformation/transformers/es6/parameters/index.js
@@ -0,0 +1,11 @@
+import * as util from  "../../../../util";
+import * as visitors from "../../../../traversal/visitors";
+
+import * as def from "./default";
+import * as rest from "./rest";
+
+export var metadata = {
+  group: "builtin-advanced"
+};
+
+export var visitor = visitors.merge([rest.visitor, def.visitor]);
diff --git a/src/babel/transformation/transformers/es6/parameters.rest.js b/src/babel/transformation/transformers/es6/parameters/rest.js
similarity index 97%
rename from src/babel/transformation/transformers/es6/parameters.rest.js
rename to src/babel/transformation/transformers/es6/parameters/rest.js
index 1ccb6572c3..4d1ee7f93a 100644
--- a/src/babel/transformation/transformers/es6/parameters.rest.js
+++ b/src/babel/transformation/transformers/es6/parameters/rest.js
@@ -1,5 +1,5 @@
-import * as util from  "../../../util";
-import * as t from "../../../types";
+import * as util from  "../../../../util";
+import * as t from "../../../../types";
 
 var memberExpressionOptimisationVisitor = {
   Scope(node, parent, scope, state) {
@@ -84,7 +84,7 @@ export var visitor = {
     var argsId = t.identifier("arguments");
 
     // otherwise `arguments` will be remapped in arrow functions
-    argsId._shadowedFunctionLiteral = true;
+    argsId._shadowedFunctionLiteral = node;
 
     // support patterns
     if (t.isPattern(rest)) {
diff --git a/src/babel/transformation/transformers/es6/spread.js b/src/babel/transformation/transformers/es6/spread.js
index 698f394c59..3d5c3a3663 100644
--- a/src/babel/transformation/transformers/es6/spread.js
+++ b/src/babel/transformation/transformers/es6/spread.js
@@ -43,6 +43,10 @@ function build(props, scope) {
   return nodes;
 }
 
+export var metadata = {
+  group: "builtin-advanced"
+};
+
 export var visitor = {
   ArrayExpression(node, parent, scope) {
     var elements = node.elements;
diff --git a/src/babel/transformation/transformers/es6/tail-call.js b/src/babel/transformation/transformers/es6/tail-call.js
index 104cd65a6c..115624241f 100644
--- a/src/babel/transformation/transformers/es6/tail-call.js
+++ b/src/babel/transformation/transformers/es6/tail-call.js
@@ -211,7 +211,7 @@ class TailCallTransformer {
       var decl = t.variableDeclarator(this.argumentsId);
       if (this.argumentsId) {
         decl.init = t.identifier("arguments");
-        decl.init._shadowedFunctionLiteral = true;
+        decl.init._shadowedFunctionLiteral = node;
       }
       topVars.push(decl);
     }
diff --git a/src/babel/transformation/transformers/index.js b/src/babel/transformation/transformers/index.js
index b90d40d342..31e1bde216 100644
--- a/src/babel/transformation/transformers/index.js
+++ b/src/babel/transformation/transformers/index.js
@@ -46,9 +46,6 @@ export default {
   "es6.regex.sticky":                      require("./es6/regex.sticky"),
   "es6.regex.unicode":                     require("./es6/regex.unicode"),
   "es6.constants":                         require("./es6/constants"),
-  "es6.parameters.rest":                   require("./es6/parameters.rest"),
-  "es6.spread":                            require("./es6/spread"),
-  "es6.parameters.default":                require("./es6/parameters.default"),
   "es7.exportExtensions":                  require("./es7/export-extensions"),
   "spec.protoToAssign":                    require("babel-plugin-proto-to-assign"),
   "es7.doExpressions":                     require("./es7/do-expressions"),
@@ -57,6 +54,8 @@ export default {
   "spec.undefinedToVoid":                  require("babel-plugin-undefined-to-void"),
 
   //- builtin-advanced
+  "es6.spread":                            require("./es6/spread"),
+  "es6.parameters":                        require("./es6/parameters"),
   "es6.destructuring":                     require("./es6/destructuring"),
   "es6.blockScoping":                      require("./es6/block-scoping"),
   "es6.spec.blockScoping":                 require("./es6/spec.block-scoping"),
diff --git a/src/babel/transformation/transformers/internal/shadow-functions.js b/src/babel/transformation/transformers/internal/shadow-functions.js
index 2c8fc030f3..223cae1b82 100644
--- a/src/babel/transformation/transformers/internal/shadow-functions.js
+++ b/src/babel/transformation/transformers/internal/shadow-functions.js
@@ -10,6 +10,9 @@ function remap(path, key, create) {
 
   var fnPath = path.findParent((path) => !path.is("shadow") && (path.isFunction() || path.isProgram()));
 
+  var shadowed = path.node._shadowedFunctionLiteral;
+  if (shadowed && shadowed !== fnPath.node) return;
+
   var cached = fnPath.getData(key);
   if (cached) return cached;
 
@@ -28,7 +31,7 @@ export var visitor = {
   },
 
   ReferencedIdentifier(node) {
-    if (node.name === "arguments" && !node._shadowedFunctionLiteral) {
+    if (node.name === "arguments") {
       return remap(this, "arguments", () => t.identifier("arguments"));
     }
   }
diff --git a/src/babel/traversal/visitors.js b/src/babel/traversal/visitors.js
index fa093d71d8..b51df8b642 100644
--- a/src/babel/traversal/visitors.js
+++ b/src/babel/traversal/visitors.js
@@ -126,6 +126,8 @@ export function merge(visitors) {
   var rootVisitor = {};
 
   for (var visitor of (visitors: Array)) {
+    explode(visitor);
+
     for (var type in visitor) {
       var nodeVisitor = rootVisitor[type] = rootVisitor[type] || {};
       mergePair(nodeVisitor, visitor[type]);
diff --git a/test/core/fixtures/transformation/es6.parameters.default/before-last/actual.js b/test/core/fixtures/transformation/es6.parameters/default-before-last/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/before-last/actual.js
rename to test/core/fixtures/transformation/es6.parameters/default-before-last/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/before-last/expected.js b/test/core/fixtures/transformation/es6.parameters/default-before-last/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/before-last/expected.js
rename to test/core/fixtures/transformation/es6.parameters/default-before-last/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/destructuring/exec.js b/test/core/fixtures/transformation/es6.parameters/default-destructuring/exec.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/destructuring/exec.js
rename to test/core/fixtures/transformation/es6.parameters/default-destructuring/exec.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/eval/actual.js b/test/core/fixtures/transformation/es6.parameters/default-eval/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/eval/actual.js
rename to test/core/fixtures/transformation/es6.parameters/default-eval/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/eval/expected.js b/test/core/fixtures/transformation/es6.parameters/default-eval/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/eval/expected.js
rename to test/core/fixtures/transformation/es6.parameters/default-eval/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/iife-1128/exec.js b/test/core/fixtures/transformation/es6.parameters/default-iife-1128/exec.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/iife-1128/exec.js
rename to test/core/fixtures/transformation/es6.parameters/default-iife-1128/exec.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/multiple/actual.js b/test/core/fixtures/transformation/es6.parameters/default-multiple/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/multiple/actual.js
rename to test/core/fixtures/transformation/es6.parameters/default-multiple/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/multiple/expected.js b/test/core/fixtures/transformation/es6.parameters/default-multiple/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/multiple/expected.js
rename to test/core/fixtures/transformation/es6.parameters/default-multiple/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/single/actual.js b/test/core/fixtures/transformation/es6.parameters/default-single/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/single/actual.js
rename to test/core/fixtures/transformation/es6.parameters/default-single/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.default/single/expected.js b/test/core/fixtures/transformation/es6.parameters/default-single/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.default/single/expected.js
rename to test/core/fixtures/transformation/es6.parameters/default-single/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/arrow-functions/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-arrow-functions/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/arrow-functions/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-arrow-functions/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/arrow-functions/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-arrow-functions/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/arrow-functions/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-arrow-functions/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/async-function/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-async-function/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/async-function/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-async-function/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/async-function/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-async-function/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/async-function/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-async-function/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/async-function/options.json b/test/core/fixtures/transformation/es6.parameters/rest-async-function/options.json
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/async-function/options.json
rename to test/core/fixtures/transformation/es6.parameters/rest-async-function/options.json
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/deepest-common-ancestor-earliest-child/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/deepest-common-ancestor-earliest-child/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/deepest-common-ancestor-earliest-child/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/deepest-common-ancestor-earliest-child/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-deepest-common-ancestor-earliest-child/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/member-expression-deoptimisation/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-member-expression-deoptimisation/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/member-expression-deoptimisation/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-member-expression-deoptimisation/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/member-expression-deoptimisation/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-member-expression-deoptimisation/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/member-expression-deoptimisation/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-member-expression-deoptimisation/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/member-expression-optimisation/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-member-expression-optimisation/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/member-expression-optimisation/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-member-expression-optimisation/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/member-expression-optimisation/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-member-expression-optimisation/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/member-expression-optimisation/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-member-expression-optimisation/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/multiple/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-multiple/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/multiple/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-multiple/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/multiple/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-multiple/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/multiple/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-multiple/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/actual.js
new file mode 100644
index 0000000000..3a60098259
--- /dev/null
+++ b/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/actual.js
@@ -0,0 +1,6 @@
+function broken(x, ...foo) {
+  if (true) {
+    class Foo extends Bar { }
+    return hello(...foo)
+  }
+}
diff --git a/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/expected.js
new file mode 100644
index 0000000000..509591d150
--- /dev/null
+++ b/test/core/fixtures/transformation/es6.parameters/rest-nested-iife/expected.js
@@ -0,0 +1,35 @@
+"use strict";
+
+var _get = function get(_x, _x2, _x3) { var _again = true; _function: while (_again) { var object = _x, property = _x2, receiver = _x3; desc = parent = getter = undefined; _again = false; if (object === null) object = Function.prototype; var desc = Object.getOwnPropertyDescriptor(object, property); if (desc === undefined) { var parent = Object.getPrototypeOf(object); if (parent === null) { return undefined; } else { _x = parent; _x2 = property; _x3 = receiver; _again = true; continue _function; } } else if ("value" in desc) { return desc.value; } else { var getter = desc.get; if (getter === undefined) { return undefined; } return getter.call(receiver); } } };
+
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) subClass.__proto__ = superClass; }
+
+function broken(x) {
+  for (var _len = arguments.length, foo = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+    foo[_key - 1] = arguments[_key];
+  }
+
+  if (true) {
+    var _ret = (function () {
+      var Foo = (function (_Bar) {
+        function Foo() {
+          _classCallCheck(this, Foo);
+
+          _get(Object.getPrototypeOf(Foo.prototype), "constructor", this).apply(this, arguments);
+        }
+
+        _inherits(Foo, _Bar);
+
+        return Foo;
+      })(Bar);
+
+      return {
+        v: hello.apply(undefined, foo)
+      };
+    })();
+
+    if (typeof _ret === "object") return _ret.v;
+  }
+}
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/pattern/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-pattern/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/pattern/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-pattern/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/pattern/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-pattern/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/pattern/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-pattern/expected.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/spread-optimisation/actual.js b/test/core/fixtures/transformation/es6.parameters/rest-spread-optimisation/actual.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/spread-optimisation/actual.js
rename to test/core/fixtures/transformation/es6.parameters/rest-spread-optimisation/actual.js
diff --git a/test/core/fixtures/transformation/es6.parameters.rest/spread-optimisation/expected.js b/test/core/fixtures/transformation/es6.parameters/rest-spread-optimisation/expected.js
similarity index 100%
rename from test/core/fixtures/transformation/es6.parameters.rest/spread-optimisation/expected.js
rename to test/core/fixtures/transformation/es6.parameters/rest-spread-optimisation/expected.js