diff --git a/scrapy/crawler.py b/scrapy/crawler.py
index 0754276f3..d121e90a5 100644
--- a/scrapy/crawler.py
+++ b/scrapy/crawler.py
@@ -64,6 +64,13 @@ class Crawler(object):
         self.crawling = True
 
         try:
+            # Support multiple calls to crawl()
+            if self.settings.frozen:
+                # Dirty hack, this should probably be more like
+                # self.settings = self.settings.mutable_copy()
+                # or maybe
+                # self.settings.unfreeze()
+                self.settings.frozen = False
             self.spider = self._create_spider(*args, **kwargs)
             self.spider.update_settings(self.settings)
             self.settings.freeze()