diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 06f0a691c4..2cc37d6ae1 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -143,8 +143,11 @@ your [`$PATH`](http://unix.stackexchange.com/questions/26047/how-to-correctly-ad
 
 + [trim-right](http://ghub.io/trim-right) Trims the rightside whitespace.
 
-+ [user-home](http://ghub.io/user-home) Gets the users home directory. This is used to resolve the babel-node/babel/register cache.
++ [path-exists](https://www.npmjs.com/package/path-exists) Checks if a path exists. (replaces the deprecated `fs.exists` methods)
 
++ [home-or-tmp](https://github.com/sindresorhus/home-or-tmp) Gets the user home directory with fallback to the system temporary directory. This is used to resolve the babel-node/babel/register cache.
+
++ [resolve](https://www.npmjs.com/package/resolve) Implements the [`require.resolve()` algorithm](http://nodejs.org/docs/v0.12.0/api/all.html#all_require_resolve) such that we can `require.resolve()` on behalf of a file asynchronously and synchronously.
 
 #### Code Standards
 
diff --git a/doc/node-props.md b/doc/node-props.md
index b44470d196..3fec49b615 100644
--- a/doc/node-props.md
+++ b/doc/node-props.md
@@ -1,5 +1,5 @@
 # Properties of nodes
-These are properties babel stores in AST node objects for internal use, as opposed to properties that are part of the AST spec (ESTree at the time of this writing).
+These are properties babel stores in AST node objects for internal use, as opposed to properties that are part of the AST spec ([ESTree](https://github.com/estree/estree) at the time of this writing).
 
 ## `_blockHoist`
 `node._blockHoist != null` triggers the [block-hoist transformer](/src/babel/transformation/transformers/internal/block-hoist.js). Value should be `true` or an integer in the range `0..3`. `true` is equivalent to `2`. The value indicates whether the node should be hoisted and to what degree. See the source code for more detailed information.
@@ -8,4 +8,4 @@ These are properties babel stores in AST node objects for internal use, as oppos
 Stores a representation of a node's position in the tree and relationship to other nodes.
 
 ## `shadow`
-A truthy value on a function node triggers the [shadow-functions transformer](/src/babel/transformation/transformers/internal/shadow-functions.js), which transforms the node so that it references (or inherits) `arguments` and `this` from the parent scope. It is invoked for arrow functions, for example.
+A truthy value on a function node triggers the [shadow-functions transformer](/src/babel/transformation/transformers/internal/shadow-functions.js), which transforms the node so that it references (or inherits) `arguments` and the `this` context from the parent scope. It is invoked for arrow functions, for example.
diff --git a/packages/build-runtime.js b/packages/build-runtime.js
index 89902d08f5..962126bfa4 100644
--- a/packages/build-runtime.js
+++ b/packages/build-runtime.js
@@ -73,7 +73,6 @@ each(File.helpers, function (helperName) {
 writeFile("regenerator/index.js", readFile("regenerator/runtime-module", true));
 writeFile("regenerator/runtime.js", selfContainify(readFile("regenerator/runtime")));
 
-//
 
 var coreDefinitions = require("babel-plugin-runtime/lib/definitions");
 
@@ -93,6 +92,5 @@ each(paths, function (path) {
   writeFile("core-js/" + path + ".js", defaultify('require("core-js/library/fn/' + path + '")'));
 });
 
-//
 
 updatePackage();
diff --git a/src/babel/generation/index.js b/src/babel/generation/index.js
index a24ade6484..149002bdc2 100644
--- a/src/babel/generation/index.js
+++ b/src/babel/generation/index.js
@@ -57,34 +57,16 @@ class CodeGenerator {
     return format;
   }
 
-  static findCommonStringDelimiter(code, tokens) {
-    var occurences = {
-      single: 0,
-      double: 0
-    };
-
-    var checked = 0;
-
-    for (var i = 0; i < tokens.length; i++) {
-      var token = tokens[i];
-      if (token.type.label !== "string") continue;
-
-      var raw = code.slice(token.start, token.end);
-      if (raw[0] === "'") {
-        occurences.single++;
-      } else {
-        occurences.double++;
-      }
-
-      checked++;
-      if (checked >= 3) break;
+  static findCommonStringDelimiter(code, tokens, occurences = {"'": 0, "\"": 0}) {
+    if (tokens.length === 0 || occurences["'"] + occurences["\""] >= 3) {
+      return occurences["'"] > occurences["\""] ? "single" : "double";
     }
 
-    if (occurences.single > occurences.double) {
-      return "single";
-    } else {
-      return "double";
+    if (tokens[0].type.label === "string") {
+      occurences[code[tokens[0].start]]++;
     }
+
+    return this.findCommonStringDelimiter(code, tokens.slice(1), occurences);
   }
 
   static generators = {
diff --git a/src/babel/messages.js b/src/babel/messages.js
index f06f248083..8b8fd7d0d4 100644
--- a/src/babel/messages.js
+++ b/src/babel/messages.js
@@ -1,7 +1,7 @@
 import * as util from  "util";
 
 export const MESSAGES = {
-  tailCallReassignmentDeopt: "Function reference has been reassigned so it's probably be dereferenced so we can't optimise this with confidence",
+  tailCallReassignmentDeopt: "Function reference has been reassigned, so it will probably be dereferenced, therefore we can't optimise this with confidence",
   JSXNamespacedTags: "Namespace tags are not supported. ReactJSX is not XML.",
   classesIllegalBareSuper: "Illegal use of bare super",
   classesIllegalSuperCall: "Direct super call is illegal in non-constructor, use super.$1() instead",
@@ -17,7 +17,7 @@ export const MESSAGES = {
   missingTemplatesDirectory: "no templates directory - this is most likely the result of a broken `npm publish`. Please report to https://github.com/babel/babel/issues",
   unsupportedOutputType: "Unsupported output type $1",
   illegalMethodName: "Illegal method name $1",
-  lostTrackNodePath: "We lost track of this nodes position, likely because the AST was directly manipulated",
+  lostTrackNodePath: "We lost track of this node's position, likely because the AST was directly manipulated",
 
   modulesIllegalExportName: "Illegal export $1",
   modulesDuplicateDeclarations: "Duplicate module declarations with the same source but in different scopes",
@@ -26,7 +26,7 @@ export const MESSAGES = {
   undeclaredVariableType: "Referencing a type alias outside of a type annotation",
   undeclaredVariableSuggestion: "Reference to undeclared variable $1 - did you mean $2?",
 
-  traverseNeedsParent: "Must pass a scope and parentPath unless traversing a Program/File got a $1 node",
+  traverseNeedsParent: "You must pass a scope and parentPath unless traversing a Program/File got a $1 node",
   traverseVerifyRootFunction: "You passed `traverse()` a function when it expected a visitor object, are you sure you didn't mean `{ enter: Function }`?",
   traverseVerifyVisitorProperty: "You passed `traverse()` a visitor object with the property $1 that has the invalid property $2",
   traverseVerifyNodeType: "You gave us a visitor for the node type $1 but it's not a valid type",
@@ -37,7 +37,7 @@ export const MESSAGES = {
   pluginNotTransformer: "The plugin $1 didn't export a Plugin instance",
   pluginUnknown: "Unknown plugin $1",
 
-  pluginNotFile: "Plugin $1 is resolving to a different Babel version to what is doing the actual transformation..."
+  pluginNotFile: "Plugin $1 is resolving to a different Babel version than what is performing the transformation."
 };
 
 export function get(key: String, ...args) {
diff --git a/src/babel/traversal/scope/index.js b/src/babel/traversal/scope/index.js
index 158c85388a..646666738c 100644
--- a/src/babel/traversal/scope/index.js
+++ b/src/babel/traversal/scope/index.js
@@ -146,7 +146,7 @@ export default class Scope {
     }
 
     var cached = path.getData("scope");
-    if (cached && cached.parent === parent) {
+    if (cached && cached.parent === parent && cached.block === path.node) {
       return cached;
     } else {
       path.setData("scope", this);
diff --git a/test/core/fixtures/transformation/es6.classes/constructor/actual.js b/test/core/fixtures/transformation/es6.classes/constructor/actual.js
index c968e6c108..33c274123a 100644
--- a/test/core/fixtures/transformation/es6.classes/constructor/actual.js
+++ b/test/core/fixtures/transformation/es6.classes/constructor/actual.js
@@ -10,3 +10,12 @@ class Foo extends Bar {
     this.state = "test";
   }
 }
+
+class ConstructorScoping {
+  constructor(){
+    let bar;
+    {
+      let bar;
+    }
+  }
+}
diff --git a/test/core/fixtures/transformation/es6.classes/constructor/expected.js b/test/core/fixtures/transformation/es6.classes/constructor/expected.js
index 7169ce082f..9aefa96a1c 100644
--- a/test/core/fixtures/transformation/es6.classes/constructor/expected.js
+++ b/test/core/fixtures/transformation/es6.classes/constructor/expected.js
@@ -16,4 +16,13 @@ var Foo = (function (_Bar) {
 
   babelHelpers.inherits(Foo, _Bar);
   return Foo;
-})(Bar);
\ No newline at end of file
+})(Bar);
+
+var ConstructorScoping = function ConstructorScoping() {
+  babelHelpers.classCallCheck(this, ConstructorScoping);
+
+  var bar = undefined;
+  {
+    var _bar = undefined;
+  }
+};