diff --git a/lib/util.js b/lib/util.js
index 31e638ae..2b6c6681 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -11,7 +11,7 @@ var log = new Logger(Logger.WARNING);
 var path = require('path');
 
 exports.findCommonBase = function(files) {
-  if (!files || files.length === 1) return '';
+  if (!files || files.length === 0) return '';
   var lastSlash = files[0].lastIndexOf(path.sep);
   if (!lastSlash) return '';
   var first = files[0].substr(0, lastSlash + 1);