diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a90d4b9f4..132aa7f628 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -143,7 +143,7 @@ See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
   * The `Literal` node type has been unoverloaded and split into `BooleanLiteral`, `RegExpLiteral`, `NumericLiteral`, `StringLiteral` and `NullLiteral`.
   * The `SpreadProperty` (from `object-rest-spread`) node type has been split into `RestProperty` (for `ObjectPattern`) and `SpreadProperty` (for `ObjectExpression`)
   * Remove `module.exports` export interop for CommonJS module formatter.
-  * `externalHelpers` option has been moved into the plugin `babel-plugin-external-helper-2`.
+  * `externalHelpers` option has been moved into the plugin `babel-plugin-external-helpers-2`.
  * **New Feature**
   * Add plugin options.
   * Add callable class constructor.
diff --git a/Makefile b/Makefile
index 84f67b1d48..20f49dcddf 100644
--- a/Makefile
+++ b/Makefile
@@ -31,10 +31,12 @@ test-clean:
 	rm -rf packages/*/test/tmp
 	rm -rf packages/*/test-fixtures.json
 
-test: lint
+test-only:
 	./scripts/test.sh
 	make test-clean
 
+test: lint test-only
+
 test-cov: clean
 	BABEL_ENV=test; \
 	gulp build
diff --git a/packages/babel-core/package.json b/packages/babel-core/package.json
index 5441963c30..79970f5dd6 100644
--- a/packages/babel-core/package.json
+++ b/packages/babel-core/package.json
@@ -50,7 +50,7 @@
     "regenerator": "0.8.35",
     "shebang-regex": "^1.0.0",
     "slash": "^1.0.0",
-    "source-map": "^0.4.0",
+    "source-map": "^0.5.0",
     "source-map-support": "^0.2.10"
   },
   "devDependencies": {
diff --git a/packages/babel-core/test/_transformation-helper.js b/packages/babel-core/test/_transformation-helper.js
index 8ebe82db41..588d64df02 100644
--- a/packages/babel-core/test/_transformation-helper.js
+++ b/packages/babel-core/test/_transformation-helper.js
@@ -107,8 +107,8 @@ function run(task, done) {
         }
       };
 
-      var fn = new Function("require", "done", "exports", execCode);
-      fn.call(global, fakeRequire, chai.assert, {}, done);
+      var fn = new Function("require", "assert", "exports", "done", "transform", execCode);
+      fn.call(global, fakeRequire, chai.assert, {}, done, transform);
     } catch (err) {
       err.message = exec.loc + ": " + err.message;
       err.message += codeFrame(execCode);
diff --git a/packages/babel-core/test/fixtures/plugins/regression-2772/exec.js b/packages/babel-core/test/fixtures/plugins/regression-2772/exec.js
new file mode 100644
index 0000000000..558dbeaa02
--- /dev/null
+++ b/packages/babel-core/test/fixtures/plugins/regression-2772/exec.js
@@ -0,0 +1,37 @@
+var code = `
+(function() {
+  function foo(b){
+    b === "lol";
+    foo(b);
+  }
+})();
+`;
+
+transform(code, {
+  plugins: [
+    function (b) {
+      var t = b.types;
+      return {
+        visitor: {
+          // Replace block statements with a new node without changing anything
+          BlockStatement: function(path) {
+            if (path.node.seen) {
+              return;
+            }
+            var node = t.blockStatement(path.node.body);
+            node.seen = true;
+            path.replaceWith(node);
+          },
+          // do type inference
+          BinaryExpression: function(path) {
+            var left  = path.get("left");
+            var right = path.get("right");
+            left.baseTypeStrictlyMatches(right);
+          }
+        }
+      };
+    }
+  ],
+  compact: true,
+  comments: false,
+}).code;
diff --git a/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/actual.js b/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/actual.js
new file mode 100644
index 0000000000..c6400ef2fa
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/actual.js
@@ -0,0 +1,6 @@
+let obj = {
+  a: 123,
+  async foo(bar) {
+    return await baz(bar);
+  }
+}
diff --git a/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/expected.js b/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/expected.js
new file mode 100644
index 0000000000..7628e45eca
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/async-to-generator/object-method/expected.js
@@ -0,0 +1,8 @@
+let obj = {
+  a: 123,
+  foo(bar) {
+    return babelHelpers.asyncToGenerator(function* () {
+      return yield baz(bar);
+    })();
+  }
+};
diff --git a/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/actual.js b/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/actual.js
new file mode 100644
index 0000000000..76170bb418
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/actual.js
@@ -0,0 +1 @@
+export default class extends A {}
diff --git a/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/expected.js b/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/expected.js
new file mode 100644
index 0000000000..62032a4013
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/es6.classes/export-super-class/expected.js
@@ -0,0 +1,12 @@
+var _class = (function (_A) {
+  babelHelpers.inherits(_class, _A);
+
+  function _class() {
+    babelHelpers.classCallCheck(this, _class);
+    return babelHelpers.possibleConstructorReturn(this, Object.getPrototypeOf(_class).apply(this, arguments));
+  }
+
+  return _class;
+})(A);
+
+export default _class;
diff --git a/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/actual.js b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/actual.js
new file mode 100644
index 0000000000..b637888826
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/actual.js
@@ -0,0 +1,5 @@
+export default function (number) {
+    if (!isNaN(number)) {
+        return 1;
+    }
+}
diff --git a/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/expected.js b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/expected.js
new file mode 100644
index 0000000000..b637888826
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/non-typeof/expected.js
@@ -0,0 +1,5 @@
+export default function (number) {
+    if (!isNaN(number)) {
+        return 1;
+    }
+}
diff --git a/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/options.json b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/options.json
new file mode 100644
index 0000000000..a9b95ca6a3
--- /dev/null
+++ b/packages/babel-core/test/fixtures/transformation/transform-es2015-typeof-symbol/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-es2015-typeof-symbol"]
+}
diff --git a/packages/babel-core/test/plugins.js b/packages/babel-core/test/plugins.js
new file mode 100644
index 0000000000..93adae6413
--- /dev/null
+++ b/packages/babel-core/test/plugins.js
@@ -0,0 +1 @@
+require("./_transformation-helper").run("plugins");
diff --git a/packages/babel-generator/package.json b/packages/babel-generator/package.json
index bd369d8c1a..ffa5d59da0 100644
--- a/packages/babel-generator/package.json
+++ b/packages/babel-generator/package.json
@@ -18,7 +18,7 @@
     "is-integer": "^1.0.4",
     "lodash": "^3.10.1",
     "repeating": "^1.1.3",
-    "source-map": "^0.4.4",
+    "source-map": "^0.5.0",
     "trim-right": "^1.0.1"
   },
   "devDependencies": {
diff --git a/packages/babel-helper-remap-async-to-generator/src/index.js b/packages/babel-helper-remap-async-to-generator/src/index.js
index 453f4c52ad..8a08e58ec4 100644
--- a/packages/babel-helper-remap-async-to-generator/src/index.js
+++ b/packages/babel-helper-remap-async-to-generator/src/index.js
@@ -24,7 +24,7 @@ let awaitVisitor = {
   }
 };
 
-function classMethod(path: NodePath, callId: Object) {
+function classOrObjectMethod(path: NodePath, callId: Object) {
   let node = path.node;
   let body = node.body;
 
@@ -99,8 +99,8 @@ export default function (path: NodePath, callId: Object) {
 
   path.traverse(awaitVisitor);
 
-  if (path.isClassMethod()) {
-    return classMethod(path, callId);
+  if (path.isClassMethod() || path.isObjectMethod()) {
+    return classOrObjectMethod(path, callId);
   } else {
     return plainFunction(path, callId);
   }
diff --git a/packages/babel-messages/src/index.js b/packages/babel-messages/src/index.js
index 53a769f1b1..5c136dc5f2 100644
--- a/packages/babel-messages/src/index.js
+++ b/packages/babel-messages/src/index.js
@@ -56,7 +56,7 @@ export function get(key: string, ...args): string {
 
   // replace $0 placeholders with args
   return msg.replace(/\$(\d+)/g, function (str, i) {
-    return args[--i];
+    return args[i - 1];
   });
 }
 
diff --git a/packages/babel-plugin-transform-es2015-classes/src/index.js b/packages/babel-plugin-transform-es2015-classes/src/index.js
index 887890d343..9dc92babbb 100644
--- a/packages/babel-plugin-transform-es2015-classes/src/index.js
+++ b/packages/babel-plugin-transform-es2015-classes/src/index.js
@@ -8,13 +8,15 @@ export default function ({ types: t }) {
       ClassDeclaration(path) {
         let { node } = path;
 
+        let ref = node.id || path.scope.generateUidIdentifier("class");
+
         if (path.parentPath.isExportDefaultDeclaration()) {
           path = path.parentPath;
-          path.insertAfter(t.exportDefaultDeclaration(node.id));
+          path.insertAfter(t.exportDefaultDeclaration(ref));
         }
 
         path.replaceWith(t.variableDeclaration("let", [
-          t.variableDeclarator(node.id, t.toExpression(node))
+          t.variableDeclarator(ref, t.toExpression(node))
         ]));
       },
 
diff --git a/packages/babel-plugin-transform-es2015-typeof-symbol/src/index.js b/packages/babel-plugin-transform-es2015-typeof-symbol/src/index.js
index a3da0e6267..08df2600a8 100644
--- a/packages/babel-plugin-transform-es2015-typeof-symbol/src/index.js
+++ b/packages/babel-plugin-transform-es2015-typeof-symbol/src/index.js
@@ -6,7 +6,7 @@ export default function ({ types: t }) {
       UnaryExpression(path) {
         let { node, parent } = path;
         if (node[IGNORE]) return;
-        if (path.find(path => !!path.node._generated)) return;
+        if (path.find(path => path.node && !!path.node._generated)) return;
 
         if (path.parentPath.isBinaryExpression() && t.EQUALITY_BINARY_OPERATORS.indexOf(parent.operator) >= 0) {
           // optimise `typeof foo === "string"` since we can determine that they'll never need to handle symbols
diff --git a/packages/babel-plugin-transform-regenerator/lib/visit.js b/packages/babel-plugin-transform-regenerator/lib/visit.js
index 0f68ffc686..c4a0d2efb2 100644
--- a/packages/babel-plugin-transform-regenerator/lib/visit.js
+++ b/packages/babel-plugin-transform-regenerator/lib/visit.js
@@ -146,6 +146,10 @@ function getOuterFnExpr(funPath) {
   var node = funPath.node;
   t.assertFunction(node);
 
+  if (!node.id) {
+    node.id = funPath.scope.parent.generateUidIdentifier("callee");
+  }
+
   if (node.generator && // Non-generator functions don't need to be marked.
       t.isFunctionDeclaration(node)) {
     var pp = funPath.findParent(function (path) {
@@ -171,9 +175,7 @@ function getOuterFnExpr(funPath) {
     );
   }
 
-  return node.id || (
-    node.id = funPath.scope.parent.generateUidIdentifier("callee")
-  );
+  return node.id;
 }
 
 function getRuntimeMarkDecl(blockPath) {
diff --git a/packages/babel-polyfill/scripts/build-dist.sh b/packages/babel-polyfill/scripts/build-dist.sh
index 38f8477688..db5b2bd2ed 100755
--- a/packages/babel-polyfill/scripts/build-dist.sh
+++ b/packages/babel-polyfill/scripts/build-dist.sh
@@ -12,6 +12,6 @@ node $BROWSERIFY_CMD lib/index.js \
   --plugin derequire/plugin \
   >dist/polyfill.js
 node $UGLIFY_CMD dist/polyfill.js \
-  --compress warnings=false \
-  --mangle \
+  --compress keep_fnames,keep_fargs,warnings=false \
+  --mangle keep_fnames \
   >dist/polyfill.min.js
diff --git a/packages/babel-preset-react/index.js b/packages/babel-preset-react/index.js
index b488ccb658..327f02e403 100644
--- a/packages/babel-preset-react/index.js
+++ b/packages/babel-preset-react/index.js
@@ -4,5 +4,6 @@ module.exports = {
     require("babel-plugin-transform-flow-strip-types"),
     require("babel-plugin-syntax-flow"),
     require("babel-plugin-syntax-jsx"),
+    require("babel-plugin-transform-react-display-name"),
   ]
 };
diff --git a/packages/babel-preset-react/package.json b/packages/babel-preset-react/package.json
index c71eb9e293..11d4a13297 100644
--- a/packages/babel-preset-react/package.json
+++ b/packages/babel-preset-react/package.json
@@ -10,7 +10,8 @@
   "dependencies": {
     "babel-plugin-syntax-flow": "^6.0.14",
     "babel-plugin-syntax-jsx": "^6.0.14",
-    "babel-plugin-transform-react-jsx": "^6.0.14",
-    "babel-plugin-transform-flow-strip-types": "^6.0.14"
+    "babel-plugin-transform-flow-strip-types": "^6.0.14",
+    "babel-plugin-transform-react-display-name": "^6.0.14",
+    "babel-plugin-transform-react-jsx": "^6.0.14"
   }
 }