diff --git a/scrapy/contrib/spidermiddleware/offsite.py b/scrapy/contrib/spidermiddleware/offsite.py
index 3ce50ae28..f8acbf8d8 100644
--- a/scrapy/contrib/spidermiddleware/offsite.py
+++ b/scrapy/contrib/spidermiddleware/offsite.py
@@ -44,8 +44,7 @@ class OffsiteMiddleware(object):
         allowed_domains = getattr(spider, 'allowed_domains', None)
         if not allowed_domains:
             return re.compile('') # allow all by default
-        domains = [d.replace('.', r'\.') for d in allowed_domains]
-        regex = r'^(.*\.)?(%s)$' % '|'.join(domains)
+        regex = r'^(.*\.)?(%s)$' % '|'.join(re.escape(d) for d in allowed_domains)
         return re.compile(regex)
 
     def spider_opened(self, spider):
diff --git a/scrapy/tests/test_spidermiddleware_offsite.py b/scrapy/tests/test_spidermiddleware_offsite.py
index b7f09dd02..fd6e43753 100644
--- a/scrapy/tests/test_spidermiddleware_offsite.py
+++ b/scrapy/tests/test_spidermiddleware_offsite.py
@@ -23,7 +23,11 @@ class TestOffsiteMiddleware(TestCase):
                        Request('http://sub.scrapy.org/1'),
                        Request('http://offsite.tld/letmepass', dont_filter=True)]
         offsite_reqs = [Request('http://scrapy2.org'),
-                       Request('http://offsite.tld/')]
+                       Request('http://offsite.tld/'),
+                       Request('http://offsite.tld/scrapytest.org'),
+                       Request('http://offsite.tld/rogue.scrapytest.org'),
+                       Request('http://rogue.scrapytest.org.haha.com'),
+                       Request('http://roguescrapytest.org')]
         reqs = onsite_reqs + offsite_reqs
 
         out = list(self.mw.process_spider_output(res, reqs, self.spider))