diff --git a/react-packager/src/ModuleGraph/node-haste/node-haste.flow.js b/react-packager/src/ModuleGraph/node-haste/node-haste.flow.js
index cae82416..9d0cf00b 100644
--- a/react-packager/src/ModuleGraph/node-haste/node-haste.flow.js
+++ b/react-packager/src/ModuleGraph/node-haste/node-haste.flow.js
@@ -9,6 +9,10 @@
  * @flow
  */
 
+'use strict';
+
+import DependencyGraphHelpers from '../../node-haste/DependencyGraph/DependencyGraphHelpers';
+
 type ModuleID = string;
 export type Path = string;
 type Platform = string;
@@ -45,21 +49,10 @@ export type FastFS = {
   matches(directory: Path, pattern: RegExp): Array<Path>,
 };
 
-type HelpersOptions = {|
-  assetExts: Extensions,
-  providesModuleNodeModules: Array<string>,
-|};
-
-declare class Helpers {
-  // node-haste/DependencyGraph/DependencyGraphHelpers.js
-  constructor(options: HelpersOptions): void,
-}
-export type HelpersT = Helpers;
-
 type DeprecatedAssetMapOptions = {|
   assetExts: Extensions,
   files: Array<Path>,
-  helpers: Helpers,
+  helpers: DependencyGraphHelpers,
   platforms: Platforms,
 |};
 
@@ -74,7 +67,7 @@ type HasteMapOptions = {|
   fastfs: FastFS,
   moduleCache: ModuleCache,
   preferNativePlatform: true,
-  helpers: Helpers,
+  helpers: DependencyGraphHelpers,
   platforms: Platforms,
 |};
 
@@ -90,7 +83,7 @@ type ResolutionRequestOptions = {|
   preferNativePlatform: true,
   hasteMap: HasteMap,
   deprecatedAssetMap: DeprecatedAssetMap,
-  helpers: Helpers,
+  helpers: DependencyGraphHelpers,
   moduleCache: ModuleCache,
   fastfs: FastFS,
   shouldThrowOnUnresolvedErrors: () => true,
diff --git a/react-packager/src/ModuleGraph/node-haste/node-haste.js b/react-packager/src/ModuleGraph/node-haste/node-haste.js
index 6013e689..8a0ff3b9 100644
--- a/react-packager/src/ModuleGraph/node-haste/node-haste.js
+++ b/react-packager/src/ModuleGraph/node-haste/node-haste.js
@@ -15,7 +15,6 @@ import type { // eslint-disable-line sort-requires
   DeprecatedAssetMapT,
   Extensions,
   HasteMapT,
-  HelpersT,
   Path,
   ResolutionRequestT,
 } from './node-haste.flow';
@@ -25,7 +24,7 @@ import type {
   TransformedFile,
 } from '../types.flow';
 
-const DependencyGraphHelpers: Class<HelpersT> = require('../../node-haste/DependencyGraph/DependencyGraphHelpers');
+const DependencyGraphHelpers = require('../../node-haste/DependencyGraph/DependencyGraphHelpers');
 const DeprecatedAssetMap: Class<DeprecatedAssetMapT> = require('../../node-haste/DependencyGraph/DeprecatedAssetMap');
 const FastFS = require('./FastFS');
 const HasteMap: Class<HasteMapT> = require('../../node-haste/DependencyGraph/HasteMap');
diff --git a/react-packager/src/node-haste/DependencyGraph/DependencyGraphHelpers.js b/react-packager/src/node-haste/DependencyGraph/DependencyGraphHelpers.js
index 6f5d9916..355c3ce8 100644
--- a/react-packager/src/node-haste/DependencyGraph/DependencyGraphHelpers.js
+++ b/react-packager/src/node-haste/DependencyGraph/DependencyGraphHelpers.js
@@ -5,7 +5,10 @@
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
  */
+
 'use strict';
 
 const path = require('path');
@@ -13,12 +16,19 @@ const path = require('path');
 const NODE_MODULES = path.sep + 'node_modules' + path.sep;
 
 class DependencyGraphHelpers {
-  constructor({ providesModuleNodeModules, assetExts }) {
+
+  _providesModuleNodeModules: Array<string>;
+  _assetExts: Array<string>;
+
+  constructor({ providesModuleNodeModules, assetExts }: {
+    providesModuleNodeModules: Array<string>,
+    assetExts: Array<string>,
+  }) {
     this._providesModuleNodeModules = providesModuleNodeModules;
     this._assetExts = assetExts;
   }
 
-  isNodeModulesDir(file) {
+  isNodeModulesDir(file: string) {
     const index = file.lastIndexOf(NODE_MODULES);
     if (index === -1) {
       return false;
@@ -35,11 +45,11 @@ class DependencyGraphHelpers {
     return true;
   }
 
-  isAssetFile(file) {
+  isAssetFile(file: string) {
     return this._assetExts.indexOf(this.extname(file)) !== -1;
   }
 
-  extname(name) {
+  extname(name: string) {
     return path.extname(name).substr(1);
   }
 }
diff --git a/react-packager/src/node-haste/Module.js b/react-packager/src/node-haste/Module.js
index 3cea23d0..4b8072e7 100644
--- a/react-packager/src/node-haste/Module.js
+++ b/react-packager/src/node-haste/Module.js
@@ -23,6 +23,7 @@ const {join: joinPath, relative: relativePath, extname} = require('path');
 
 import type {TransformedCode} from '../JSTransformer/worker/worker';
 import type Cache from './Cache';
+import type DependencyGraphHelpers from './DependencyGraph/DependencyGraphHelpers';
 import type ModuleCache from './ModuleCache';
 import type FastFs from './fastfs';
 
@@ -44,8 +45,6 @@ export type Options = {
   cacheTransformResults?: boolean,
 };
 
-export type DepGraphHelpers = {isNodeModulesDir: (filePath: string) => boolean};
-
 export type ConstructorArgs = {
   file: string,
   fastfs: FastFs,
@@ -53,7 +52,7 @@ export type ConstructorArgs = {
   cache: Cache,
   transformCode: ?TransformCode,
   transformCacheKey: ?string,
-  depGraphHelpers: DepGraphHelpers,
+  depGraphHelpers: DependencyGraphHelpers,
   options: Options,
 };
 
@@ -67,7 +66,7 @@ class Module {
   _cache: Cache;
   _transformCode: ?TransformCode;
   _transformCacheKey: ?string;
-  _depGraphHelpers: DepGraphHelpers;
+  _depGraphHelpers: DependencyGraphHelpers;
   _options: Options;
 
   _docBlock: Promise<{id?: string, moduleDocBlock: {[key: string]: mixed}}>;
diff --git a/react-packager/src/node-haste/ModuleCache.js b/react-packager/src/node-haste/ModuleCache.js
index a963c24a..b82c2ba4 100644
--- a/react-packager/src/node-haste/ModuleCache.js
+++ b/react-packager/src/node-haste/ModuleCache.js
@@ -17,8 +17,8 @@ const Package = require('./Package');
 const Polyfill = require('./Polyfill');
 
 import type Cache from './Cache';
+import type DependencyGraphHelpers from './DependencyGraph/DependencyGraphHelpers';
 import type {
-  DepGraphHelpers,
   TransformCode,
   Options as ModuleOptions,
 } from './Module';
@@ -32,7 +32,7 @@ class ModuleCache {
   _cache: Cache;
   _transformCode: TransformCode;
   _transformCacheKey: string;
-  _depGraphHelpers: DepGraphHelpers;
+  _depGraphHelpers: DependencyGraphHelpers;
   _platforms: mixed;
   _assetDependencies: mixed;
   _moduleOptions: ModuleOptions;
@@ -52,7 +52,7 @@ class ModuleCache {
     cache: Cache,
     transformCode: TransformCode,
     transformCacheKey: string,
-    depGraphHelpers: DepGraphHelpers,
+    depGraphHelpers: DependencyGraphHelpers,
     assetDependencies: mixed,
     moduleOptions: ModuleOptions,
   }, platforms: mixed) {
diff --git a/react-packager/src/node-haste/index.js b/react-packager/src/node-haste/index.js
index 1397723b..8fcdda7a 100644
--- a/react-packager/src/node-haste/index.js
+++ b/react-packager/src/node-haste/index.js
@@ -59,7 +59,7 @@ class DependencyGraph {
     forceNodeFilesystemAPI: boolean,
     assetRoots_DEPRECATED: Array<string>,
     assetExts: Array<string>,
-    providesModuleNodeModules: mixed,
+    providesModuleNodeModules: Array<string>,
     platforms: Set<mixed>,
     preferNativePlatform: boolean,
     extensions: Array<string>,
@@ -118,7 +118,7 @@ class DependencyGraph {
     forceNodeFilesystemAPI?: boolean,
     assetRoots_DEPRECATED: Array<string>,
     assetExts: Array<string>,
-    providesModuleNodeModules: mixed,
+    providesModuleNodeModules: Array<string>,
     platforms: mixed,
     preferNativePlatform: boolean,
     cache: Cache,