diff --git a/tasks/grunt-karma.js b/tasks/grunt-karma.js
index 7070a4a..4911d18 100644
--- a/tasks/grunt-karma.js
+++ b/tasks/grunt-karma.js
@@ -82,6 +82,7 @@ module.exports = function(grunt) {
           return obj;
         });
       }));
+      data.files = _.flatten(data.files);
     }
 
     // Allow the use of templates in preprocessors