diff --git a/lib/file.js b/lib/file.js
index e34c10e4..01f3a895 100644
--- a/lib/file.js
+++ b/lib/file.js
@@ -35,7 +35,7 @@ File.prototype.open = function() {
 };
 
 File.prototype.toJSON = function() {
-  return {
+  var json = {
     size: this.size,
     path: this.path,
     name: this.name,
@@ -45,6 +45,10 @@ File.prototype.toJSON = function() {
     filename: this.filename,
     mime: this.mime
   };
+  if (this.hash && this.hash != "") {
+    json.hash = this.hash;
+  }
+  return json;
 };
 
 File.prototype.write = function(buffer, cb) {