diff --git a/react-packager/src/DependencyResolver/DependencyGraph/HasteMap.js b/react-packager/src/DependencyResolver/DependencyGraph/HasteMap.js
index e1626fef..38d27e3e 100644
--- a/react-packager/src/DependencyResolver/DependencyGraph/HasteMap.js
+++ b/react-packager/src/DependencyResolver/DependencyGraph/HasteMap.js
@@ -7,7 +7,6 @@
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 'use strict';
-
 const path = require('path');
 const getPlatformExtension = require('../lib/getPlatformExtension');
 const Promise = require('promise');
@@ -118,11 +117,12 @@ class HasteMap {
 
     const moduleMap = this._map[name];
     const modulePlatform = getPlatformExtension(mod.path) || GENERIC_PLATFORM;
+    const existingModule = moduleMap[modulePlatform];
 
-    if (moduleMap[modulePlatform]) {
+    if (existingModule && existingModule.path !== mod.path) {
       throw new Error(
         `Naming collision detected: ${mod.path} ` +
-        `collides with ${moduleMap[modulePlatform].path}`
+        `collides with ${existingModule.path}`
       );
     }
 
diff --git a/react-packager/src/DependencyResolver/DependencyGraph/__tests__/DependencyGraph-test.js b/react-packager/src/DependencyResolver/DependencyGraph/__tests__/DependencyGraph-test.js
index a89ce97a..d830cc82 100644
--- a/react-packager/src/DependencyResolver/DependencyGraph/__tests__/DependencyGraph-test.js
+++ b/react-packager/src/DependencyResolver/DependencyGraph/__tests__/DependencyGraph-test.js
@@ -3821,6 +3821,36 @@ describe('DependencyGraph', function() {
         });
       });
     });
+
+    pit('should not error when the watcher reports a known file as added', function() {
+      var root = '/root';
+      fs.__setMockFilesystem({
+        'root': {
+          'index.js': [
+            '/**',
+            ' * @providesModule index',
+            ' */',
+            'var b = require("b");',
+          ].join('\n'),
+          'b.js': [
+            '/**',
+            ' * @providesModule b',
+            ' */',
+            'module.exports = function() {};',
+          ].join('\n'),
+        },
+      });
+
+      var dgraph = new DependencyGraph({
+        ...defaults,
+        roots: [root],
+      });
+
+      return getOrderedDependenciesAsJSON(dgraph, '/root/index.js').then(function() {
+        triggerFileChange('add', 'index.js', root, mockStat);
+        return getOrderedDependenciesAsJSON(dgraph, '/root/index.js');
+      });
+    });
   });
 
   describe('getAsyncDependencies', () => {