diff --git a/scrapy/contrib/httpcache.py b/scrapy/contrib/httpcache.py
index 0891c6355..49e82dc8c 100644
--- a/scrapy/contrib/httpcache.py
+++ b/scrapy/contrib/httpcache.py
@@ -163,7 +163,8 @@ class DbmCacheStorage(object):
     def __init__(self, settings):
         self.cachedir = data_path(settings['HTTPCACHE_DIR'], createdir=True)
         self.expiration_secs = settings.getint('HTTPCACHE_EXPIRATION_SECS')
-        self.dbmodule = __import__(settings['HTTPCACHE_DBM_MODULE'])
+        self.dbmodule = __import__(settings['HTTPCACHE_DBM_MODULE'],
+                                   {}, {}, [''])
         self.db = None
 
     def open_spider(self, spider):