diff --git a/src/babel/transformation/transformers/es6/block-scoping.js b/src/babel/transformation/transformers/es6/block-scoping.js
index 7782417bdf..1cde2dee72 100644
--- a/src/babel/transformation/transformers/es6/block-scoping.js
+++ b/src/babel/transformation/transformers/es6/block-scoping.js
@@ -32,8 +32,8 @@ function isVar(node, parent) {
 }
 
 function standardizeLets(declars) {
-  for (var i = 0; i < declars.length; i++) {
-    delete declars[i]._let;
+  for (var declar of (declars: Array)) {
+    delete declar._let;
   }
 }
 
@@ -109,19 +109,14 @@ function traverseReplace(node, parent, scope, remaps) {
 }
 
 var letReferenceBlockVisitor = {
-  enter(node, parent, scope, state) {
-    if (this.isFunction()) {
-      this.traverse(letReferenceFunctionVisitor, state);
-      return this.skip();
-    }
+  Function(node, parent, scope, state) {
+    this.traverse(letReferenceFunctionVisitor, state);
+    return this.skip();
   }
 };
 
 var letReferenceFunctionVisitor = {
-  enter(node, parent, scope, state) {
-    // not a direct reference
-    if (!this.isReferencedIdentifier()) return;
-
+  ReferencedIdentifier(node, parent, scope, state) {
     var ref = state.letReferences[node.name];
 
     // not a part of our scope
@@ -159,10 +154,8 @@ var hoistVarDeclarationsVisitor = {
 };
 
 var loopLabelVisitor = {
-  enter(node, parent, scope, state) {
-    if (this.isLabeledStatement()) {
-      state.innerLabels.push(node.label.name);
-    }
+  LabeledStatement(node, parent, scope, state) {
+    state.innerLabels.push(node.label.name);
   }
 };
 
diff --git a/src/babel/traversal/scope.js b/src/babel/traversal/scope.js
index ab94b3d6bc..db5681f2c6 100644
--- a/src/babel/traversal/scope.js
+++ b/src/babel/traversal/scope.js
@@ -430,8 +430,8 @@ export default class Scope {
       this.registerBinding("hoisted", path);
     } else if (t.isVariableDeclaration(node)) {
       var declarations = path.get("declarations");
-      for (var i = 0; i < declarations.length; i++) {
-        this.registerBinding(node.kind, declarations[i]);
+      for (var declar of (declarations: Array)) {
+        this.registerBinding(node.kind, declar);
       }
     } else if (t.isClassDeclaration(node)) {
       this.registerBinding("let", path);
@@ -548,8 +548,8 @@ export default class Scope {
     // ForStatement - left, init
 
     if (path.isLoop()) {
-      for (let i = 0; i < t.FOR_INIT_KEYS.length; i++) {
-        var node = path.get(t.FOR_INIT_KEYS[i]);
+      for (let key of (t.FOR_INIT_KEYS: Array)) {
+        var node = path.get(key);
         if (node.isBlockScoped()) this.registerBinding(node.node.kind, node);
       }
     }
@@ -572,8 +572,8 @@ export default class Scope {
 
     if (path.isFunction()) {
       var params = path.get("params");
-      for (let i = 0; i < params.length; i++) {
-        this.registerBinding("param", params[i]);
+      for (let param of (params: Array)) {
+        this.registerBinding("param", param);
       }
       this.traverse(path.get("body").node, blockVariableVisitor, this);
     }
@@ -697,8 +697,7 @@ export default class Scope {
   getAllBindingsOfKind(): Object {
     var ids = object();
 
-    for (let i = 0; i < arguments.length; i++) {
-      var kind = arguments[i];
+    for (let kind of (arguments: Array)) {
       var scope = this;
       do {
         for (var name in scope.bindings) {
@@ -789,6 +788,19 @@ export default class Scope {
     return this.parent && this.parent.hasBinding(name);
   }
 
+  /**
+   * Move a binding of `name` to another `scope`.
+   */
+
+  moveBindingTo(name, scope) {
+    var info = this.getBinding(name);
+    if (info) {
+      info.scope.removeOwnBinding(name);
+      info.scope = scope;
+      scope.bindings[name] = info;
+    }
+  }
+
   /**
    * Description
    */