diff --git a/gulpfile.js b/gulpfile.js
index d126eea..974c553 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -66,7 +66,7 @@ gulp.task('prepare-release', function() {
             .pipe(tar('slack-' + version + '.tar'))
             .pipe(gzip())
     )
-    .pipe(chmod(0644))
+    .pipe(chmod(644))
     .pipe(gulp.dest('release'));
 });