diff --git a/lib/exec.js b/lib/exec.js
index 05cddb2..67ec5d0 100644
--- a/lib/exec.js
+++ b/lib/exec.js
@@ -18,8 +18,9 @@ module.exports = function exec() {
 
 	// console.log(cmd + ' ' + args.join(' '));
 
-	// somehow stderr and stdout are reversed from doc?
 	child_process.execFile(cmd, args, opts, function (error, stderr, stdout) {
-		callback(error ? new Error(stderr) : null, stdout);
+
+		// somehow stderr and stdout are reversed local
+		return callback(error ? new Error(stderr || stdout) : null, stdout || stderr);
 	});
 };