diff --git a/src/babel/transformation/file/index.js b/src/babel/transformation/file/index.js
index aa4cb57b79..75e844f61a 100644
--- a/src/babel/transformation/file/index.js
+++ b/src/babel/transformation/file/index.js
@@ -41,10 +41,11 @@ export default class File {
     this.dynamicImportIds   = {};
     this.dynamicImports     = [];
 
-    this.usedHelpers = {};
-    this.dynamicData = {};
-    this.data        = {};
-    this.uids        = {};
+    this.declarations = {};
+    this.usedHelpers  = {};
+    this.dynamicData  = {};
+    this.data         = {};
+    this.uids         = {};
 
     this.log  = new Logger(this, opts.filename || "unknown");
     this.opts = this.normalizeOptions(opts);
@@ -395,8 +396,8 @@ export default class File {
 
     var program = this.ast.program;
 
-    var declar = program._declarations && program._declarations[name];
-    if (declar) return declar.id;
+    var declar = this.declarations[name];
+    if (declar) return declar;
 
     this.usedHelpers[name] = true;
 
@@ -413,11 +414,11 @@ export default class File {
 
     var ref = util.template("helper-" + name);
     ref._compact = true;
-    var uid = this.scope.generateUidIdentifier(name);
+    var uid = this.declarations[name] = this.scope.generateUidIdentifier(name);
     this.scope.push({
-      key: name,
       id: uid,
-      init: ref
+      init: ref,
+      unique: true
     });
     return uid;
   }
diff --git a/src/babel/transformation/transformers/es6/spec.symbols.js b/src/babel/transformation/transformers/es6/spec.symbols.js
index 58cfe09f36..61dc672266 100644
--- a/src/babel/transformation/transformers/es6/spec.symbols.js
+++ b/src/babel/transformation/transformers/es6/spec.symbols.js
@@ -21,3 +21,7 @@ export function UnaryExpression(node, parent, scope, file) {
     }
   }
 }
+
+export function VariableDeclaration(node) {
+  if (node._generated) this.skip();
+}
diff --git a/src/babel/transformation/transformers/index.js b/src/babel/transformation/transformers/index.js
index 5d94722f50..1ec845d14a 100644
--- a/src/babel/transformation/transformers/index.js
+++ b/src/babel/transformation/transformers/index.js
@@ -94,8 +94,6 @@ export default {
 
   "spec.protoToAssign":                    require("./spec/proto-to-assign"),
 
-  _declarations:                           require("./internal/declarations"),
-
   _shadowFunctions:                        require("./internal/shadow-functions"),
 
   "es7.doExpressions":                     require("./es7/do-expressions"),
diff --git a/src/babel/transformation/transformers/internal/declarations.js b/src/babel/transformation/transformers/internal/declarations.js
deleted file mode 100644
index c8977eeb22..0000000000
--- a/src/babel/transformation/transformers/internal/declarations.js
+++ /dev/null
@@ -1,37 +0,0 @@
-import * as strict from "../../helpers/strict";
-import * as t from "../../../types";
-
-export var metadata = {
-  secondPass: true
-};
-
-export function BlockStatement(node, parent, scope, file) {
-  if (!node._declarations) return;
-
-  strict.wrap(node, function () {
-    var kinds = {};
-    var kind;
-
-    for (var i in node._declarations) {
-      var declar = node._declarations[i];
-
-      kind = declar.kind || "var";
-      var declarNode = t.variableDeclarator(declar.id, declar.init);
-
-      if (declar.init) {
-        node.body.unshift(file.attachAuxiliaryComment(t.variableDeclaration(kind, [declarNode])));
-      } else {
-        kinds[kind] ||= [];
-        kinds[kind].push(declarNode);
-      }
-    }
-
-    for (kind in kinds) {
-      node.body.unshift(file.attachAuxiliaryComment(t.variableDeclaration(kind, kinds[kind])));
-    }
-
-    node._declarations = null;
-  });
-}
-
-export { BlockStatement as Program };
diff --git a/src/babel/traversal/index.js b/src/babel/traversal/index.js
index ced192cb23..65112715d2 100644
--- a/src/babel/traversal/index.js
+++ b/src/babel/traversal/index.js
@@ -76,7 +76,7 @@ traverse.node = function (node, opts, scope, state, parentPath) {
 
 const CLEAR_KEYS = [
   "trailingComments", "leadingComments", "extendedRange",
-  "_declarations", "_scopeInfo" ,"_paths",
+  "_scopeInfo" ,"_paths",
   "tokens", "range", "start", "end", "loc", "raw"
 ];
 
diff --git a/src/babel/traversal/scope.js b/src/babel/traversal/scope.js
index f28592f337..a8e89724fa 100644
--- a/src/babel/traversal/scope.js
+++ b/src/babel/traversal/scope.js
@@ -516,23 +516,35 @@ export default class Scope {
    */
 
   push(opts: Object) {
-    var block = this.block;
+    var path = this.path;
 
-    if (t.isLoop(block) || t.isCatchClause(block) || t.isFunction(block)) {
-      t.ensureBlock(block);
-      block = block.body;
+    if (path.isLoop() || path.isCatchClause() || path.isFunction()) {
+      t.ensureBlock(path.node);
+      path = path.get("body");
     }
 
-    if (!t.isBlockStatement(block) && !t.isProgram(block)) {
-      block = this.getBlockParent().block;
+    if (!path.isBlockStatement() && !path.isProgram()) {
+      path = this.getBlockParent().path;
     }
 
-    block._declarations ||= {};
-    block._declarations[opts.key || opts.id.name] = {
-      kind: opts.kind || "var",
-      id: opts.id,
-      init: opts.init
-    };
+    var unique = opts.unique;
+    var kind   = opts.kind || "var";
+
+    var dataKey = `declaration:${kind}`;
+    var declar  = !unique && path.getData(dataKey);
+
+    if (!declar) {
+      declar = t.variableDeclaration(opts.kind || "var", []);
+      declar._generated = true;
+      declar._blockHoist = 2;
+
+      this.file.attachAuxiliaryComment(declar);
+
+      path.get("body")[0]._containerInsertBefore([declar]);
+      if (!unique) path.setData(dataKey, declar);
+    }
+
+    declar.declarations.push(t.variableDeclarator(opts.id, opts.init));
   }
 
   /**
diff --git a/src/babel/types/index.js b/src/babel/types/index.js
index 1b7dbb75d2..312916c0fc 100644
--- a/src/babel/types/index.js
+++ b/src/babel/types/index.js
@@ -282,12 +282,11 @@ export function inheritsComments(child: Object, parent: Object): Object {
 export function inherits(child: Object, parent: Object): Object {
   if (!child || !parent) return child;
 
-  child._declarations = parent._declarations;
-  child._scopeInfo    = parent._scopeInfo;
-  child.range         = parent.range;
-  child.start         = parent.start;
-  child.loc           = parent.loc;
-  child.end           = parent.end;
+  child._scopeInfo = parent._scopeInfo;
+  child.range      = parent.range;
+  child.start      = parent.start;
+  child.loc        = parent.loc;
+  child.end        = parent.end;
 
   child.typeAnnotation = parent.typeAnnotation;
   child.returnType     = parent.returnType;
diff --git a/test/core/fixtures/transformation/es6.modules-amd/exports-default/expected.js b/test/core/fixtures/transformation/es6.modules-amd/exports-default/expected.js
index 3dfc0ccccd..68260cbd5b 100644
--- a/test/core/fixtures/transformation/es6.modules-amd/exports-default/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-amd/exports-default/expected.js
@@ -29,4 +29,4 @@ define(["exports", "module"], function (exports, module) {
 
   module.exports = Foo;
   module.exports = foo;
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-amd/exports-from/expected.js b/test/core/fixtures/transformation/es6.modules-amd/exports-from/expected.js
index db5a7c3606..b20489db6f 100644
--- a/test/core/fixtures/transformation/es6.modules-amd/exports-from/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-amd/exports-from/expected.js
@@ -1,14 +1,14 @@
 define(["exports", "foo"], function (exports, _foo) {
   "use strict";
 
-  var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
-
-  var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
 
+  var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
+
+  var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
+
   _defaults(exports, _interopRequireWildcard(_foo));
 
   Object.defineProperty(exports, "foo", {
diff --git a/test/core/fixtures/transformation/es6.modules-amd/exports-variable/expected.js b/test/core/fixtures/transformation/es6.modules-amd/exports-variable/expected.js
index 9150d0f7c9..26a1aab376 100644
--- a/test/core/fixtures/transformation/es6.modules-amd/exports-variable/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-amd/exports-variable/expected.js
@@ -1,11 +1,12 @@
 define(["exports"], function (exports) {
   "use strict";
 
-  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
+
+  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
   exports.foo7 = foo7;
   var foo = 1;
   exports.foo = foo;
@@ -31,4 +32,4 @@ define(["exports"], function (exports) {
   };
 
   exports.foo8 = foo8;
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-amd/overview/expected.js b/test/core/fixtures/transformation/es6.modules-amd/overview/expected.js
index fd9a892fd3..4349443d83 100644
--- a/test/core/fixtures/transformation/es6.modules-amd/overview/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-amd/overview/expected.js
@@ -1,12 +1,12 @@
 define(["exports", "foo", "foo-bar", "./directory/foo-bar"], function (exports, _foo, _fooBar, _directoryFooBar) {
   "use strict";
 
-  var _interopRequire = function (obj) { return obj && obj.__esModule ? obj["default"] : obj; };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
 
+  var _interopRequire = function (obj) { return obj && obj.__esModule ? obj["default"] : obj; };
+
   var _foo2 = _interopRequire(_foo);
 
   exports.test = test;
@@ -19,4 +19,4 @@ define(["exports", "foo", "foo-bar", "./directory/foo-bar"], function (exports,
   _foo;
   _foo.bar;
   _foo.foo;
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-common/exports-default/expected.js b/test/core/fixtures/transformation/es6.modules-common/exports-default/expected.js
index 483aa14736..1e0024e612 100644
--- a/test/core/fixtures/transformation/es6.modules-common/exports-default/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-common/exports-default/expected.js
@@ -1,10 +1,11 @@
 "use strict";
 
-var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
+
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
 exports["default"] = foo;
 exports["default"] = 42;
 exports["default"] = {};
diff --git a/test/core/fixtures/transformation/es6.modules-common/exports-from/expected.js b/test/core/fixtures/transformation/es6.modules-common/exports-from/expected.js
index 9ab68d6c9d..0637083f05 100644
--- a/test/core/fixtures/transformation/es6.modules-common/exports-from/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-common/exports-from/expected.js
@@ -1,13 +1,13 @@
 "use strict";
 
-var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
-
-var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
 
+var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
+
+var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
+
 var _foo = require("foo");
 
 _defaults(exports, _interopRequireWildcard(_foo));
diff --git a/test/core/fixtures/transformation/es6.modules-common/exports-variable/expected.js b/test/core/fixtures/transformation/es6.modules-common/exports-variable/expected.js
index ef2947462f..872031c988 100644
--- a/test/core/fixtures/transformation/es6.modules-common/exports-variable/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-common/exports-variable/expected.js
@@ -1,10 +1,11 @@
 "use strict";
 
-var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
+
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
 exports.foo7 = foo7;
 var foo = 1;
 exports.foo = foo;
@@ -29,4 +30,4 @@ var foo8 = function foo8() {
   _classCallCheck(this, foo8);
 };
 
-exports.foo8 = foo8;
+exports.foo8 = foo8;
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-system/exports-default/expected.js b/test/core/fixtures/transformation/es6.modules-system/exports-default/expected.js
index d9113b298e..e55e897b43 100644
--- a/test/core/fixtures/transformation/es6.modules-system/exports-default/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-system/exports-default/expected.js
@@ -1,5 +1,7 @@
 System.register([], function (_export) {
-  var _classCallCheck, _default, Foo;
+  var _default, Foo;
+
+  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
 
   _export("default", foo);
 
@@ -10,8 +12,6 @@ System.register([], function (_export) {
     execute: function () {
       "use strict";
 
-      _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
       _export("default", 42);
 
       _export("default", {});
@@ -39,4 +39,4 @@ System.register([], function (_export) {
       _export("default", Foo);
     }
   };
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-system/exports-variable/expected.js b/test/core/fixtures/transformation/es6.modules-system/exports-variable/expected.js
index 5006e12bbf..6b0a9eb768 100644
--- a/test/core/fixtures/transformation/es6.modules-system/exports-variable/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-system/exports-variable/expected.js
@@ -1,5 +1,7 @@
 System.register([], function (_export) {
-  var _classCallCheck, foo, foo2, foo3, foo4, foo5, foo6, foo8;
+  var foo, foo2, foo3, foo4, foo5, foo6, foo8;
+
+  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
 
   _export("foo7", foo7);
 
@@ -10,8 +12,6 @@ System.register([], function (_export) {
     execute: function () {
       "use strict";
 
-      _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
       foo = 1;
 
       _export("foo", foo);
@@ -43,4 +43,4 @@ System.register([], function (_export) {
       _export("foo3", foo3 = 5);
     }
   };
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/es6.modules-umd/exports-from/expected.js b/test/core/fixtures/transformation/es6.modules-umd/exports-from/expected.js
index 85293a2999..3ba9443e48 100644
--- a/test/core/fixtures/transformation/es6.modules-umd/exports-from/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-umd/exports-from/expected.js
@@ -13,14 +13,14 @@
 })(this, function (exports, _foo) {
   "use strict";
 
-  var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
-
-  var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
 
+  var _interopRequireWildcard = function (obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (typeof obj === "object" && obj !== null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj["default"] = obj; return newObj; } };
+
+  var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
+
   _defaults(exports, _interopRequireWildcard(_foo));
 
   Object.defineProperty(exports, "foo", {
diff --git a/test/core/fixtures/transformation/es6.modules-umd/exports-variable/expected.js b/test/core/fixtures/transformation/es6.modules-umd/exports-variable/expected.js
index c806e52afa..b9c310ceb2 100644
--- a/test/core/fixtures/transformation/es6.modules-umd/exports-variable/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-umd/exports-variable/expected.js
@@ -13,11 +13,12 @@
 })(this, function (exports) {
   "use strict";
 
-  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
+
+  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
   exports.foo7 = foo7;
   var foo = 1;
   exports.foo = foo;
diff --git a/test/core/fixtures/transformation/es6.modules-umd/overview/expected.js b/test/core/fixtures/transformation/es6.modules-umd/overview/expected.js
index 8000493eb7..59d94a1102 100644
--- a/test/core/fixtures/transformation/es6.modules-umd/overview/expected.js
+++ b/test/core/fixtures/transformation/es6.modules-umd/overview/expected.js
@@ -13,12 +13,12 @@
 })(this, function (exports, _foo, _fooBar, _directoryFooBar) {
   "use strict";
 
-  var _interopRequire = function (obj) { return obj && obj.__esModule ? obj["default"] : obj; };
-
   Object.defineProperty(exports, "__esModule", {
     value: true
   });
 
+  var _interopRequire = function (obj) { return obj && obj.__esModule ? obj["default"] : obj; };
+
   var _foo2 = _interopRequire(_foo);
 
   exports.test = test;
@@ -29,4 +29,4 @@
 
   _foo.bar;
   _foo.foo;
-});
+});
\ No newline at end of file
diff --git a/test/core/fixtures/transformation/spec.proto-to-assign/assignment-expression/expected.js b/test/core/fixtures/transformation/spec.proto-to-assign/assignment-expression/expected.js
index c562f1f1e7..8efad04c17 100644
--- a/test/core/fixtures/transformation/spec.proto-to-assign/assignment-expression/expected.js
+++ b/test/core/fixtures/transformation/spec.proto-to-assign/assignment-expression/expected.js
@@ -1,11 +1,11 @@
 "use strict";
 
-var _foo, _foo$bar, _foo$bar2;
-
 var _defaults = function (obj, defaults) { var keys = Object.getOwnPropertyNames(defaults); for (var i = 0; i < keys.length; i++) { var key = keys[i]; var value = Object.getOwnPropertyDescriptor(defaults, key); if (value && value.configurable && obj[key] === undefined) { Object.defineProperty(obj, key, value); } } return obj; };
 
+var _foo, _foo$bar, _foo$bar2;
+
 console.log((_foo = foo, _defaults(_foo, bar), _foo));
 
 console.log((_foo$bar = foo[bar], _defaults(_foo$bar, bar), _foo$bar));
 
-console.log((_foo$bar2 = foo[bar()], _defaults(_foo$bar2, bar), _foo$bar2));
+console.log((_foo$bar2 = foo[bar()], _defaults(_foo$bar2, bar), _foo$bar2));
\ No newline at end of file