diff --git a/lib/6to5/transformation/file.js b/lib/6to5/transformation/file.js
index b20d46a9fc..393da69764 100644
--- a/lib/6to5/transformation/file.js
+++ b/lib/6to5/transformation/file.js
@@ -18,9 +18,10 @@ var each       = require("lodash/collection/each");
 var t          = require("../types");
 
 function File(opts) {
-  this.dynamicImportIds = {};
-  this.dynamicImported  = [];
-  this.dynamicImports   = [];
+  this.dynamicImportedNoDefault = [];
+  this.dynamicImportIds         = {};
+  this.dynamicImported          = [];
+  this.dynamicImports           = [];
 
   this.dynamicData      = {};
   this.data             = {};
@@ -273,7 +274,7 @@ File.prototype.get = function (key) {
   }
 };
 
-File.prototype.addImport = function (source, name) {
+File.prototype.addImport = function (source, name, noDefault) {
   name = name || source;
   var id = this.dynamicImportIds[name];
 
@@ -283,7 +284,9 @@ File.prototype.addImport = function (source, name) {
     var specifiers = [t.importSpecifier(t.identifier("default"), id)];
     var declar = t.importDeclaration(specifiers, t.literal(source));
     declar._blockHoist = 3;
+
     this.dynamicImported.push(declar);
+    if (noDefault) this.dynamicImportedNoDefault.push(declar);
 
     this.moduleFormatter.importSpecifier(specifiers[0], declar, this.dynamicImports);
   }
diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index d05567668c..004670b6fd 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -4,10 +4,10 @@ module.exports = AMDFormatter;
 
 var DefaultFormatter = require("./_default");
 var CommonFormatter  = require("./common");
-var util             = require("../../util");
-var t                = require("../../types");
 var includes         = require("lodash/collection/includes");
 var values           = require("lodash/object/values");
+var util             = require("../../util");
+var t                = require("../../types");
 
 function AMDFormatter() {
   CommonFormatter.apply(this, arguments);
@@ -81,12 +81,12 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
   var ref = this.getExternalReference(node);
 
-  if (includes(this.file.dynamicImported, node)) {
+  if (includes(this.file.dynamicImportedNoDefault, node)) {
     // Prevent unnecessary renaming of dynamic imports.
     this.ids[node.source.value] = ref;
   } else if (t.isImportBatchSpecifier(specifier)) {
     // import * as bar from "foo";
-  } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequireImport) {
+  } else if (!includes(this.file.dynamicImported, node) && t.isSpecifierDefault(specifier) && !this.noInteropRequireImport) {
     // import foo from "foo";
     ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
   } else {
diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index d5c3d5d94e..4333c5294a 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -31,8 +31,8 @@ CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes)
 
   // import foo from "foo";
   if (t.isSpecifierDefault(specifier)) {
-    if (!includes(this.file.dynamicImported, node)) {
-      if (this.noInteropRequireImport) {
+    if (!includes(this.file.dynamicImportedNoDefault, node)) {
+      if (this.noInteropRequireImport || includes(this.file.dynamicImported, node)) {
         ref = t.memberExpression(ref, t.identifier("default"));
       } else {
         ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
diff --git a/lib/6to5/transformation/templates/self-contained-helpers-head.js b/lib/6to5/transformation/templates/self-contained-helpers-head.js
new file mode 100644
index 0000000000..78cc1934e6
--- /dev/null
+++ b/lib/6to5/transformation/templates/self-contained-helpers-head.js
@@ -0,0 +1,2 @@
+var helpers = exports.default = {};
+exports.__esModule = true;
diff --git a/lib/6to5/transformation/transformer.js b/lib/6to5/transformation/transformer.js
index 31bf351efb..4361e3784e 100644
--- a/lib/6to5/transformation/transformer.js
+++ b/lib/6to5/transformation/transformer.js
@@ -55,6 +55,8 @@ Transformer.prototype.normalize = function (transformer) {
       return;
     }
 
+    if (type === "enter" || type === "exit") return;
+
     if (isFunction(fns)) fns = { enter: fns };
 
     if (!isObject(fns)) return;
diff --git a/lib/6to5/transformation/transformers/index.js b/lib/6to5/transformation/transformers/index.js
index 118e50352d..155ca3042c 100644
--- a/lib/6to5/transformation/transformers/index.js
+++ b/lib/6to5/transformation/transformers/index.js
@@ -86,11 +86,12 @@ module.exports = {
   _declarations:                           require("./internal/declarations"),
 
   _aliasFunctions:                         require("./internal/alias-functions"),
-  _moduleFormatter:                        require("./internal/module-formatter"),
 
   "spec.typeofSymbol":                     require("./spec/typeof-symbol"),
   "spec.undefinedToVoid":                  require("./spec/undefined-to-void"),
 
+  _moduleFormatter:                        require("./internal/module-formatter"),
+
   "es3.propertyLiterals":                  require("./es3/property-literals"),
   "es3.memberExpressionLiterals":          require("./es3/member-expression-literals"),
 
diff --git a/lib/6to5/transformation/transformers/internal/module-formatter.js b/lib/6to5/transformation/transformers/internal/module-formatter.js
index da60d60a4b..d1982280c4 100644
--- a/lib/6to5/transformation/transformers/internal/module-formatter.js
+++ b/lib/6to5/transformation/transformers/internal/module-formatter.js
@@ -2,11 +2,9 @@
 
 var useStrict = require("../../helpers/use-strict");
 
-exports.post = function (file) {
+exports.Program = function (program, parent, scope, file) {
   if (!file.transformers["es6.modules"].canRun()) return;
 
-  var program = file.ast.program;
-
   useStrict.wrap(program, function () {
     program.body = file.dynamicImports.concat(program.body);
   });
diff --git a/lib/6to5/transformation/transformers/other/bluebird-coroutines.js b/lib/6to5/transformation/transformers/other/bluebird-coroutines.js
index b32a5f14bb..c626f07ec1 100644
--- a/lib/6to5/transformation/transformers/other/bluebird-coroutines.js
+++ b/lib/6to5/transformation/transformers/other/bluebird-coroutines.js
@@ -15,7 +15,7 @@ exports.Function = function (node, parent, scope, file) {
 
   return remapAsyncToGenerator(
     node,
-    t.memberExpression(file.addImport("bluebird"), t.identifier("coroutine")),
+    t.memberExpression(file.addImport("bluebird", null, true), t.identifier("coroutine")),
     scope
   );
 };
diff --git a/lib/6to5/transformation/transformers/other/self-contained.js b/lib/6to5/transformation/transformers/other/self-contained.js
index 0267ef16f9..0c040b5ab0 100644
--- a/lib/6to5/transformation/transformers/other/self-contained.js
+++ b/lib/6to5/transformation/transformers/other/self-contained.js
@@ -78,8 +78,8 @@ exports.manipulateOptions = function (opts) {
   if (opts.whitelist.length) opts.whitelist.push("es6.modules");
 };
 
-exports.post = function (file) {
-  file.scope.traverse(file.ast, astVisitor, file);
+exports.Program = function (node, parent, scope, file) {
+  scope.traverse(node, astVisitor, file);
 };
 
 exports.pre = function (file) {
diff --git a/lib/6to5/transformation/transformers/other/use-strict.js b/lib/6to5/transformation/transformers/other/use-strict.js
index fa5462911b..92be48e0f1 100644
--- a/lib/6to5/transformation/transformers/other/use-strict.js
+++ b/lib/6to5/transformation/transformers/other/use-strict.js
@@ -3,8 +3,7 @@
 var useStrict = require("../../helpers/use-strict");
 var t         = require("../../../types");
 
-exports.post = function (file) {
-  var program = file.ast.program;
+exports.Program = function (program) {
   if (!useStrict.has(program)) {
     program.body.unshift(t.expressionStatement(t.literal("use strict")));
   }
diff --git a/lib/6to5/traversal/path.js b/lib/6to5/traversal/path.js
index f80fda064e..08220853b0 100644
--- a/lib/6to5/traversal/path.js
+++ b/lib/6to5/traversal/path.js
@@ -109,7 +109,7 @@ TraversalPath.prototype.call = function (key) {
   if (!node) return;
 
   var opts = this.opts;
-  var fn   = opts[key];
+  var fn   = opts[key] || opts;
   if (opts[node.type]) fn = opts[node.type][key] || fn;
 
   var replacement = fn.call(this, node, this.parent, this.scope, this.state);
diff --git a/lib/6to5/util.js b/lib/6to5/util.js
index 510fcec17e..8f658885a4 100644
--- a/lib/6to5/util.js
+++ b/lib/6to5/util.js
@@ -109,6 +109,8 @@ exports.template = function (name, nodes, keepExpression) {
     traverse(template, templateVisitor, null, nodes);
   }
 
+  if (template.body.length > 1) return template.body;
+
   var node = template.body[0];
 
   if (!keepExpression && t.isExpressionStatement(node)) {
diff --git a/packages/build-runtime.js b/packages/build-runtime.js
index f900403827..be6955f64a 100644
--- a/packages/build-runtime.js
+++ b/packages/build-runtime.js
@@ -2,6 +2,7 @@
 
 var buildHelpers = require("../lib/6to5/build-helpers");
 var transform    = require("../lib/6to5/transformation");
+var util         = require("../lib/6to5/util");
 var fs           = require("fs");
 var t            = require("../lib/6to5/types");
 var _            = require("lodash");
@@ -16,8 +17,14 @@ var writeFile = function (filename, content) {
   fs.writeFileSync(filename, content);
 };
 
-var readFile = function (filename) {
-  return fs.readFileSync(require.resolve(filename), "utf8");
+var readFile = function (filename, defaultify) {
+  var file = fs.readFileSync(require.resolve(filename), "utf8");
+
+  if (defaultify) {
+    file += '\nmodule.exports = { "default": module.exports, __esModule: true };\n';
+  }
+
+  return file;
 };
 
 var updatePackage = function () {
@@ -37,10 +44,10 @@ var selfContainify = function (code) {
 };
 
 var buildHelpers2 = function () {
-  var body = [];
+  var body = util.template("self-contained-helpers-head");
   var tree = t.program(body);
 
-  buildHelpers(body, t.identifier("exports"));
+  buildHelpers(body, t.identifier("helpers"));
 
   return transform.fromAst(tree, null, {
     optional: ["selfContained"]
@@ -48,7 +55,7 @@ var buildHelpers2 = function () {
 };
 
 writeFile("helpers.js", buildHelpers2());
-writeFile("core-js.js", readFile("core-js/library"));
-writeFile("regenerator/index.js", readFile("regenerator-6to5/runtime-module"));
+writeFile("core-js.js", readFile("core-js/library", true));
+writeFile("regenerator/index.js", readFile("regenerator-6to5/runtime-module", true));
 writeFile("regenerator/runtime.js", selfContainify(readFile("regenerator-6to5/runtime")));
 updatePackage();
diff --git a/test/fixtures/transformation/self-contained/aliased-constructors/expected.js b/test/fixtures/transformation/self-contained/aliased-constructors/expected.js
index b517b90ea6..31ee1c4d38 100644
--- a/test/fixtures/transformation/self-contained/aliased-constructors/expected.js
+++ b/test/fixtures/transformation/self-contained/aliased-constructors/expected.js
@@ -1,7 +1,6 @@
 "use strict";
 
-var _core = require("6to5-runtime/core-js");
-
+var _core = require("6to5-runtime/core-js")["default"];
 obj.constructor === Object;
 obj.constructor === _core.Promise;
 
diff --git a/test/fixtures/transformation/self-contained/es6-for-of/expected.js b/test/fixtures/transformation/self-contained/es6-for-of/expected.js
index 0fdc4cc4f5..bdb985ddf2 100644
--- a/test/fixtures/transformation/self-contained/es6-for-of/expected.js
+++ b/test/fixtures/transformation/self-contained/es6-for-of/expected.js
@@ -1,7 +1,6 @@
 "use strict";
 
-var _core = require("6to5-runtime/core-js");
-
+var _core = require("6to5-runtime/core-js")["default"];
 for (var _iterator = _core.$for.getIterator(arr), _step; !(_step = _iterator.next()).done;) {
   var i = _step.value;
 }
diff --git a/test/fixtures/transformation/self-contained/es7-array-comprehensions/expected.js b/test/fixtures/transformation/self-contained/es7-array-comprehensions/expected.js
index 9ea3b708c6..f448a5f2f3 100644
--- a/test/fixtures/transformation/self-contained/es7-array-comprehensions/expected.js
+++ b/test/fixtures/transformation/self-contained/es7-array-comprehensions/expected.js
@@ -1,7 +1,6 @@
 "use strict";
 
-var _core = require("6to5-runtime/core-js");
-
+var _core = require("6to5-runtime/core-js")["default"];
 var arr = (function () {
   var _arr = [];
 
diff --git a/test/fixtures/transformation/self-contained/full/expected.js b/test/fixtures/transformation/self-contained/full/expected.js
index 0dc0a4d34f..da668d006d 100644
--- a/test/fixtures/transformation/self-contained/full/expected.js
+++ b/test/fixtures/transformation/self-contained/full/expected.js
@@ -1,11 +1,8 @@
 "use strict";
 
-var _regeneratorRuntime = require("6to5-runtime/regenerator");
-
-var _to5Helpers = require("6to5-runtime/helpers");
-
-var _core = require("6to5-runtime/core-js");
-
+var _core = require("6to5-runtime/core-js")["default"];
+var _regeneratorRuntime = require("6to5-runtime/regenerator")["default"];
+var _to5Helpers = require("6to5-runtime/helpers")["default"];
 var giveWord = _regeneratorRuntime.mark(function giveWord() {
   return _regeneratorRuntime.wrap(function giveWord$(context$1$0) {
     while (1) switch (context$1$0.prev = context$1$0.next) {
diff --git a/test/fixtures/transformation/self-contained/modules-amd/expected.js b/test/fixtures/transformation/self-contained/modules-amd/expected.js
index 2fecce6c30..527a0916cf 100644
--- a/test/fixtures/transformation/self-contained/modules-amd/expected.js
+++ b/test/fixtures/transformation/self-contained/modules-amd/expected.js
@@ -1,6 +1,6 @@
 define(["exports", "foo", "6to5-runtime/helpers"], function (exports, _foo, _to5RuntimeHelpers) {
   "use strict";
 
-  var _to5Helpers = _to5RuntimeHelpers;
+  var _to5Helpers = _to5RuntimeHelpers["default"];
   var foo = _to5Helpers.interopRequire(_foo);
-});
\ No newline at end of file
+});
diff --git a/test/fixtures/transformation/self-contained/modules-common/expected.js b/test/fixtures/transformation/self-contained/modules-common/expected.js
index b44940490e..fc54eaa84a 100644
--- a/test/fixtures/transformation/self-contained/modules-common/expected.js
+++ b/test/fixtures/transformation/self-contained/modules-common/expected.js
@@ -1,5 +1,4 @@
 "use strict";
 
-var _to5Helpers = require("6to5-runtime/helpers");
-
-var foo = _to5Helpers.interopRequire(require("foo"));
\ No newline at end of file
+var _to5Helpers = require("6to5-runtime/helpers")["default"];
+var foo = _to5Helpers.interopRequire(require("foo"));
diff --git a/test/fixtures/transformation/self-contained/modules-system/expected.js b/test/fixtures/transformation/self-contained/modules-system/expected.js
index 25cbba4dc5..15b44e0942 100644
--- a/test/fixtures/transformation/self-contained/modules-system/expected.js
+++ b/test/fixtures/transformation/self-contained/modules-system/expected.js
@@ -4,10 +4,10 @@ System.register(["6to5-runtime/helpers"], function (_export) {
   var _to5Helpers;
   return {
     setters: [function (_to5RuntimeHelpers) {
-      _to5Helpers = _to5RuntimeHelpers;
+      _to5Helpers = _to5RuntimeHelpers["default"];
     }],
     execute: function () {
       foo.apply(undefined, _to5Helpers.toConsumableArray(bar));
     }
   };
-});
\ No newline at end of file
+});
diff --git a/test/fixtures/transformation/self-contained/modules-umd/expected.js b/test/fixtures/transformation/self-contained/modules-umd/expected.js
index 99db3c218f..f77b369f4e 100644
--- a/test/fixtures/transformation/self-contained/modules-umd/expected.js
+++ b/test/fixtures/transformation/self-contained/modules-umd/expected.js
@@ -7,6 +7,6 @@
 })(function (exports, _foo, _to5RuntimeHelpers) {
   "use strict";
 
-  var _to5Helpers = _to5RuntimeHelpers;
+  var _to5Helpers = _to5RuntimeHelpers["default"];
   var foo = _to5Helpers.interopRequire(_foo);
-});
\ No newline at end of file
+});
diff --git a/test/fixtures/transformation/self-contained/regenerator-runtime/expected.js b/test/fixtures/transformation/self-contained/regenerator-runtime/expected.js
index 275ec24ac5..2329286ee6 100644
--- a/test/fixtures/transformation/self-contained/regenerator-runtime/expected.js
+++ b/test/fixtures/transformation/self-contained/regenerator-runtime/expected.js
@@ -1,7 +1,6 @@
 "use strict";
 
-var _regeneratorRuntime = require("6to5-runtime/regenerator");
-
+var _regeneratorRuntime = require("6to5-runtime/regenerator")["default"];
 void _regeneratorRuntime.mark(function callee$0$0() {
   return _regeneratorRuntime.wrap(function callee$0$0$(context$1$0) {
     while (1) switch (context$1$0.prev = context$1$0.next) {
diff --git a/test/fixtures/transformation/self-contained/symbol-iterator-in/expected.js b/test/fixtures/transformation/self-contained/symbol-iterator-in/expected.js
index 5c74f87cbf..0abc1db265 100644
--- a/test/fixtures/transformation/self-contained/symbol-iterator-in/expected.js
+++ b/test/fixtures/transformation/self-contained/symbol-iterator-in/expected.js
@@ -1,5 +1,4 @@
 "use strict";
 
-var _core = require("6to5-runtime/core-js");
-
+var _core = require("6to5-runtime/core-js")["default"];
 _core.$for.isIterable(Object(arr));