diff --git a/lib/server.js b/lib/server.js
index de92322cc..f8dae3f7e 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -16,6 +16,7 @@ var reporter = require('./reporter');
 var helper = require('./helper');
 var EventEmitter = require('./events').EventEmitter;
 
+var log = logger.create();
 
 
 // TODO(vojta): get this whole mess under test
@@ -28,7 +29,6 @@ var start = function(injector, config, launcher, globalEmitter, preprocess, file
     injector.get('framework:' + framework);
   });
 
-  var log = logger.create();
   var filesPromise = fileList.refresh();
 
   if (config.autoWatch) {
@@ -249,7 +249,13 @@ exports.start = function(cliOptions, done) {
 
   // register all plugins
   config.plugins.forEach(function(plugin) {
-    modules.push(require(plugin));
+    if (helper.isString(plugin)) {
+      modules.push(require(plugin));
+    } else if (helper.isObject(plugin)) {
+      modules.push(plugin);
+    } else {
+      log.warn('Invalid plugin %s', plugin);
+    }
   });
 
   var injector = new di.Injector(modules);