diff --git a/react-packager/src/JSTransformer/Cache.js b/react-packager/src/JSTransformer/Cache.js
index 4761d15e..584077b6 100644
--- a/react-packager/src/JSTransformer/Cache.js
+++ b/react-packager/src/JSTransformer/Cache.js
@@ -31,6 +31,10 @@ var validateOpts = declareOpts({
     type: 'array',
     required: true,
   },
+  transformModulePath: {
+    type:'string',
+    required: true,
+  },
 });
 module.exports = Cache;
 
@@ -162,6 +166,8 @@ function cacheFilePath(options) {
   var cacheVersion = options.cacheVersion || '0';
   hash.update(cacheVersion);
 
+  hash.update(options.transformModulePath);
+
   var name = 'react-packager-cache-' + hash.digest('hex');
   return path.join(tmpdir, name);
 }
diff --git a/react-packager/src/JSTransformer/__tests__/Cache-test.js b/react-packager/src/JSTransformer/__tests__/Cache-test.js
index 7ad65818..f91490ba 100644
--- a/react-packager/src/JSTransformer/__tests__/Cache-test.js
+++ b/react-packager/src/JSTransformer/__tests__/Cache-test.js
@@ -32,10 +32,14 @@ describe('JSTransformer Cache', function() {
 
   describe('getting/setting', function() {
     it('calls loader callback for uncached file', function() {
-      var cache = new Cache({projectRoots: ['/rootDir']});
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
       var loaderCb = jest.genMockFn().mockImpl(function() {
         return Promise.resolve();
       });
+
       cache.get('/rootDir/someFile', loaderCb);
       expect(loaderCb).toBeCalledWith('/rootDir/someFile');
     });
@@ -48,10 +52,15 @@ describe('JSTransformer Cache', function() {
           }
         });
       });
-      var cache = new Cache({projectRoots: ['/rootDir']});
+
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
       var loaderCb = jest.genMockFn().mockImpl(function() {
         return Promise.resolve('lol');
       });
+
       return cache.get('/rootDir/someFile', loaderCb).then(function(value) {
         expect(value).toBe('lol');
       });
@@ -65,10 +74,15 @@ describe('JSTransformer Cache', function() {
           }
         });
       });
-      var cache = new Cache({projectRoots: ['/rootDir']});
+
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
       var loaderCb = jest.genMockFn().mockImpl(function() {
         return Promise.resolve('lol');
       });
+
       return cache.get('/rootDir/someFile', loaderCb).then(function() {
         var shouldNotBeCalled = jest.genMockFn();
         return cache.get('/rootDir/someFile', shouldNotBeCalled)
@@ -126,8 +140,12 @@ describe('JSTransformer Cache', function() {
     });
 
     pit('should load cache from disk', function() {
-      var cache = new Cache({projectRoots: ['/rootDir']});
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
       var loaderCb = jest.genMockFn();
+
       return cache.get('/rootDir/someFile', loaderCb).then(function(value) {
         expect(loaderCb).not.toBeCalled();
         expect(value).toBe('oh hai');
@@ -152,7 +170,10 @@ describe('JSTransformer Cache', function() {
         return 123;
       };
 
-      var cache = new Cache({projectRoots: ['/rootDir']});
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
       var loaderCb = jest.genMockFn().mockImpl(function() {
         return Promise.resolve('new value');
       });
@@ -193,7 +214,11 @@ describe('JSTransformer Cache', function() {
         });
       });
 
-      var cache = new Cache({projectRoots: ['/rootDir']});
+      var cache = new Cache({
+        projectRoots: ['/rootDir'],
+        transformModulePath: 'x.js',
+      });
+
       cache.get('/rootDir/bar', function() {
         return Promise.resolve('bar value');
       });
diff --git a/react-packager/src/JSTransformer/index.js b/react-packager/src/JSTransformer/index.js
index 33e01703..2dc5e20b 100644
--- a/react-packager/src/JSTransformer/index.js
+++ b/react-packager/src/JSTransformer/index.js
@@ -60,6 +60,7 @@ function Transformer(options) {
       resetCache: options.resetCache,
       cacheVersion: options.cacheVersion,
       projectRoots: options.projectRoots,
+      transformModulePath: options.transformModulePath,
     });
 
   if (options.transformModulePath != null) {