diff --git a/lib/plugin.js b/lib/plugin.js
index 0dc9310..de17947 100644
--- a/lib/plugin.js
+++ b/lib/plugin.js
@@ -60,7 +60,7 @@ ManifestPlugin.prototype.apply = function(compiler) {
   var outputName = path.relative(outputFolder, outputFile);
 
   var moduleAsset = function (module, file) {
-    if (module.userRequest) {
+    if (module.userRequest && !moduleAssets[file]) {
       moduleAssets[file] = path.join(
         path.dirname(file),
         path.basename(module.userRequest)