diff --git a/lib/importOptimized.js b/lib/importOptimized.js
index f70bb07..5370e4d 100644
--- a/lib/importOptimized.js
+++ b/lib/importOptimized.js
@@ -11,7 +11,7 @@ module.exports = function(queryOptions, params, callback) {
 
   var hashes = R.filter(function(hash) { return !!hash; }, R.map(function(file) {
     try {
-      md5File(file);
+      return md5File(file);
     } catch (e) {
       return false;
     }