diff --git a/scrapy/core/downloader/__init__.py b/scrapy/core/downloader/__init__.py
index c8d94dd71..adb7f5d9b 100644
--- a/scrapy/core/downloader/__init__.py
+++ b/scrapy/core/downloader/__init__.py
@@ -57,7 +57,6 @@ class Downloader(object):
         self.slots = {}
         self.handlers = DownloadHandlers()
         self.middleware = DownloaderMiddlewareManager.from_settings(settings)
-        self.concurrent_spiders = settings.getint('CONCURRENT_SPIDERS')
 
     def fetch(self, request, spider):
         slot = self.slots[spider]
diff --git a/scrapy/core/engine.py b/scrapy/core/engine.py
index b2c8baf07..7759ccd89 100644
--- a/scrapy/core/engine.py
+++ b/scrapy/core/engine.py
@@ -59,6 +59,7 @@ class ExecutionEngine(object):
         self.scheduler = load_object(settings['SCHEDULER'])()
         self.downloader = Downloader()
         self.scraper = Scraper(self, self.settings)
+        self._concurrent_spiders = settings.getint('CONCURRENT_SPIDERS')
         self._spider_closed_callback = spider_closed_callback
 
     @defer.inlineCallbacks
@@ -164,7 +165,7 @@ class ExecutionEngine(object):
 
     def has_capacity(self):
         """Does the engine have capacity to handle more spiders"""
-        return len(self.downloader.slots) < self.downloader.concurrent_spiders
+        return len(self.slots) < self._concurrent_spiders
 
     def crawl(self, request, spider):
         assert spider in self.open_spiders, \