diff --git a/zip.js b/zip.js
index a3316588..58dca328 100644
--- a/zip.js
+++ b/zip.js
@@ -20,8 +20,8 @@ exports.unzip = function(fileName, outputDirectory, callback, progressCallback)
     };
     var fail = function(result) {
         if (callback) {
-            callback(-1);
+            callback(-1, new Error(result));
         }
     };
     exec(win, fail, 'Zip', 'unzip', [fileName, outputDirectory]);
-};
\ No newline at end of file
+};