diff --git a/lib/cows.js b/lib/cows.js
index 8ebf14d..971ef41 100644
--- a/lib/cows.js
+++ b/lib/cows.js
@@ -32,10 +32,16 @@ exports.get = function (cow) {
 }
 
 exports.list = function (callback) {
-	fs.readdir(cowsPath, function (err, files) {
-		if (err) return callback(err);
-
-		return callback(null, cowNamesFromFiles(files));
+	return new Promise(function (resolve, reject) {
+		fs.readdir(cowsPath, function (err, files) {
+			if (err) {
+				reject(err);
+				callback(err);
+			} else {
+				resolve(files);
+				callback(null, cowNamesFromFiles(files));
+			}
+		});
 	});
 }