diff --git a/linkcheck/cache/results.py b/linkcheck/cache/results.py
new file mode 100644
index 00000000..84156fc1
--- /dev/null
+++ b/linkcheck/cache/results.py
@@ -0,0 +1,57 @@
+# -*- coding: iso-8859-1 -*-
+# Copyright (C) 2014 Bastian Kleineidam
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+"""
+Cache check results.
+"""
+from ..decorators import synchronized
+from ..lock import get_lock
+
+
+# lock object
+cache_lock = get_lock("results_cache_lock")
+
+
+class ResultCache(object):
+    """
+    Thread-safe cache of UrlData.to_wire() results.
+    the cache is limited in size since we rather recheck the same URL
+    multiple times instead of running out of memory.
+    format: {cache key (string) -> result (UrlData.towire())}
+    """
+
+    def __init__(self, max_size=10000):
+        """Initialize result cache."""
+        # mapping {URL -> cached result}
+        self.cache = {}
+        self.max_size = max_size
+        self.hits = self.misses = 0
+
+    @synchronized(cache_lock)
+    def get_result(self, key):
+        """Return cached result or None if not found."""
+        if key in self.cache:
+            self.hits += 1
+            return self.cache[key]
+        self.misses += 1
+        return None
+    
+    @synchronized(cache_lock)
+    def add_result(self, key, result):
+        if len(self.cache) > self.max_size:
+            return
+        self.cache[key] = result
+
diff --git a/linkcheck/cache/urlqueue.py b/linkcheck/cache/urlqueue.py
index fe3f26a5..8f46ef36 100644
--- a/linkcheck/cache/urlqueue.py
+++ b/linkcheck/cache/urlqueue.py
@@ -119,7 +119,7 @@ class UrlQueue (object):
         """
         if self.shutdown or self.allowed_puts == 0:
             return True
-        if url_data.cache_url_key is not None and url_data.cache_url_key in self.seen:
+        if url_data.cache_key is not None and url_data.cache_key in self.seen:
             return True
         return False
 
@@ -134,14 +134,15 @@ class UrlQueue (object):
                 return
             self.allowed_puts -= 1
         log.debug(LOG_CACHE, "queueing %s", url_data)
-        key = url_data.cache_url_key
+        key = url_data.cache_key
         if key is not None:
             if key in self.seen:
                 # don't check duplicate URLs
                 return
             self.seen.add(key)
         self.unfinished_tasks += 1
-        if url_data.has_result:
+        if url_data.has_result or \
+           (key and key[1] in url_data.aggregate.result_cache.cache):
             self.queue.appendleft(url_data)
         else:
             self.queue.append(url_data)
diff --git a/linkcheck/checker/mailtourl.py b/linkcheck/checker/mailtourl.py
index 5abaa22c..190b1a04 100644
--- a/linkcheck/checker/mailtourl.py
+++ b/linkcheck/checker/mailtourl.py
@@ -288,14 +288,13 @@ class MailtoUrl (urlbase.UrlBase):
             pass
         self.set_result(_("Valid mail address syntax"))
 
-    def set_cache_keys (self):
+    def set_cache_key(self):
         """
         The cache key is a comma separated list of emails.
         """
         emails = u",".join(sorted(self.addresses))
-        self.cache_url_key = u"%s:%s" % (self.scheme, emails)
-        assert isinstance(self.cache_url_key, unicode), self.cache_url_key
-        # cache_content_key remains None, recursion is not allowed
+        cache_url = u"%s:%s" % (self.scheme, emails)
+        self.cache_key = (self.parent_url, cache_url)
 
     def can_get_content (self):
         """
diff --git a/linkcheck/checker/urlbase.py b/linkcheck/checker/urlbase.py
index b3103f06..afb44da6 100644
--- a/linkcheck/checker/urlbase.py
+++ b/linkcheck/checker/urlbase.py
@@ -180,9 +180,8 @@ class UrlBase (object):
         self.url_connection = None
         # data of url content,  (data == None) means no data is available
         self.data = None
-        # cache keys, are set by build_url() calling set_cache_keys()
-        self.cache_url_key = None
-        self.cache_content_key = None
+        # cache key is set by build_url() calling set_cache_key()
+        self.cache_key = None
         # extern flags (is_extern, is_strict)
         self.extern = None
         # flag if the result should be cached
@@ -276,19 +275,14 @@ class UrlBase (object):
         if s not in self.info:
             self.info.append(s)
 
-    def set_cache_keys (self):
-        """
-        Set keys for URL checking and content recursion.
-        """
-        # remove anchor from content cache key since we assume
+    def set_cache_key (self):
+        """Set key for URL cache checking. A cache key consists of
+        a tuple (source url, target url)."""
+        # remove anchor from cached target url since we assume
         # URLs with different anchors to have the same content
-        self.cache_content_key = urlutil.urlunsplit(self.urlparts[:4]+[u''])
-        assert isinstance(self.cache_content_key, unicode), self
-        log.debug(LOG_CACHE, "Content cache key %r", self.cache_content_key)
-        # construct cache key
-        self.cache_url_key = self.cache_content_key
-        assert isinstance(self.cache_url_key, unicode), self
-        log.debug(LOG_CACHE, "URL cache key %r", self.cache_url_key)
+        cache_url = urlutil.urlunsplit(self.urlparts[:4]+[u''])
+        self.cache_key = (self.parent_url, cache_url)
+        log.debug(LOG_CACHE, "URL cache key %r", self.cache_key)
 
     def check_syntax (self):
         """
@@ -310,7 +304,7 @@ class UrlBase (object):
         except tuple(ExcSyntaxList) as msg:
             self.set_result(unicode_safe(msg), valid=False)
         else:
-            self.set_cache_keys()
+            self.set_cache_key()
 
     def check_url_warnings(self):
         """Check URL name and length."""
@@ -675,8 +669,8 @@ class UrlBase (object):
         assert isinstance(self.name, unicode), self
         if self.anchor is not None:
             assert isinstance(self.anchor, unicode), self
-        if self.cache_url_key is not None:
-            assert isinstance(self.cache_url_key, unicode), self
+        if self.cache_key is not None:
+            assert isinstance(self.cache_key, unicode), self
         return sep.join([
             u"%s link" % self.scheme,
             u"base_url=%r" % self.base_url,
@@ -688,7 +682,7 @@ class UrlBase (object):
             u"column=%d" % self.column,
             u"name=%r" % self.name,
             u"anchor=%r" % self.anchor,
-            u"cache_key=%r" % self.cache_url_key,
+            u"cache_key=%r" % self.cache_key,
            ])
 
     def get_intern_pattern (self, url=None):
@@ -733,7 +727,7 @@ class UrlBase (object):
         return u"<%s>" % self.serialized(sep=u", ")
 
     def to_wire_dict (self):
-        """Return a simplified transport object for logging.
+        """Return a simplified transport object for logging and caching.
 
         The transport object must contain these attributes:
         - url_data.valid: bool
@@ -764,7 +758,7 @@ class UrlBase (object):
           Line number of this URL at parent document, or -1
         - url_data.column: int
           Column number of this URL at parent document, or -1
-        - url_data.cache_url_key: unicode
+        - url_data.cache_key: unicode
           Cache key for this URL.
         - url_data.content_type: unicode
           MIME content type for URL content.
@@ -790,7 +784,7 @@ class UrlBase (object):
           info=self.info,
           line=self.line,
           column=self.column,
-          cache_url_key=self.cache_url_key,
+          cache_key=self.cache_key,
           content_type=self.get_content_type(),
           level=self.recursion_level,
           modified=self.modified,
@@ -821,7 +815,7 @@ urlDataAttr = [
     'modified',
     'line',
     'column',
-    'cache_url_key',
+    'cache_key',
     'content_type',
     'level',
 ]
diff --git a/linkcheck/director/__init__.py b/linkcheck/director/__init__.py
index 2c3db4bc..4f4508e9 100644
--- a/linkcheck/director/__init__.py
+++ b/linkcheck/director/__init__.py
@@ -22,7 +22,7 @@ import thread
 import time
 from .. import log, LOG_CHECK, LinkCheckerInterrupt, dummy, \
   fileutil, strformat, plugins
-from ..cache import urlqueue, robots_txt
+from ..cache import urlqueue, robots_txt, results
 from . import aggregator, console
 
 
@@ -207,4 +207,6 @@ def get_aggregate (config):
     _urlqueue = urlqueue.UrlQueue(max_allowed_puts=config["maxnumurls"])
     _robots_txt = robots_txt.RobotsTxt()
     plugin_manager = plugins.PluginManager(config)
-    return aggregator.Aggregate(config, _urlqueue, _robots_txt, plugin_manager)
+    result_cache = results.ResultCache()
+    return aggregator.Aggregate(config, _urlqueue, _robots_txt, plugin_manager,
+        result_cache)
diff --git a/linkcheck/director/aggregator.py b/linkcheck/director/aggregator.py
index 4f373d0e..85059e3c 100644
--- a/linkcheck/director/aggregator.py
+++ b/linkcheck/director/aggregator.py
@@ -44,7 +44,8 @@ def new_request_session(config):
 class Aggregate (object):
     """Store thread-safe data collections for checker threads."""
 
-    def __init__ (self, config, urlqueue, robots_txt, plugin_manager):
+    def __init__ (self, config, urlqueue, robots_txt, plugin_manager,
+                  result_cache):
         """Store given link checking objects."""
         self.config = config
         self.urlqueue = urlqueue
@@ -53,6 +54,7 @@ class Aggregate (object):
         self.request_sessions = {}
         self.robots_txt = robots_txt
         self.plugin_manager = plugin_manager
+        self.result_cache = result_cache
         self.times = {}
         requests_per_second = config["maxrequestspersecond"]
         self.wait_time_min = 1.0 / requests_per_second
diff --git a/linkcheck/director/checker.py b/linkcheck/director/checker.py
index b90a4890..ed140bf8 100644
--- a/linkcheck/director/checker.py
+++ b/linkcheck/director/checker.py
@@ -17,6 +17,7 @@
 """
 URL checking functions.
 """
+import copy
 from . import task
 from ..cache import urlqueue
 
@@ -28,7 +29,7 @@ def check_url (urlqueue, logger):
         try:
             if not url_data.has_result:
                 url_data.check()
-            logger.log_url(url_data)
+            logger.log_url(url_data.to_wire())
         finally:
             urlqueue.task_done(url_data)
 
@@ -53,7 +54,7 @@ class Checker (task.LoggedCheckedTask):
     def check_url (self):
         """Try to get URL data from queue and check it."""
         try:
-            url_data = self.urlqueue.get(timeout=0.1)
+            url_data = self.urlqueue.get(timeout=0.2)
             if url_data is not None:
                 try:
                     self.check_url_data(url_data)
@@ -70,6 +71,17 @@ class Checker (task.LoggedCheckedTask):
         else:
             url = url_data.url.encode("ascii", "replace")
         self.setName("CheckThread-%s" % url)
-        if not url_data.has_result:
-            url_data.check()
-        self.logger.log_url(url_data)
+        if url_data.has_result:
+            self.logger.log_url(url_data.to_wire())
+        else:
+            cache = url_data.aggregate.result_cache
+            key = url_data.cache_key[1]
+            result = cache.get_result(key)
+            if result is None:
+                url_data.check()
+                result = url_data.to_wire()
+                cache.add_result(key, result)
+            else:
+                result = copy.copy(result)
+                result.parent_url = url_data.parent_url
+            self.logger.log_url(result)
diff --git a/linkcheck/director/logger.py b/linkcheck/director/logger.py
index 5f0a9609..22fe8a70 100644
--- a/linkcheck/director/logger.py
+++ b/linkcheck/director/logger.py
@@ -60,9 +60,8 @@ class Logger (object):
         do_print = self.do_print(url_data)
         # Only send a transport object to the loggers, not the complete
         # object instance.
-        transport = url_data.to_wire()
         for log in self.loggers:
-            log.log_filter_url(transport, do_print)
+            log.log_filter_url(url_data, do_print)
 
     @synchronized(_lock)
     def log_internal_error (self):
diff --git a/linkcheck/logger/blacklist.py b/linkcheck/logger/blacklist.py
index 3d11e151..1f041fa5 100644
--- a/linkcheck/logger/blacklist.py
+++ b/linkcheck/logger/blacklist.py
@@ -55,7 +55,7 @@ class BlacklistLogger (_Logger):
         """
         Put invalid url in blacklist, delete valid url from blacklist.
         """
-        key = url_data.cache_url_key
+        key = url_data.cache_key
         if key in self.blacklist:
             if url_data.valid:
                 del self.blacklist[key]
diff --git a/tests/checker/__init__.py b/tests/checker/__init__.py
index 13a7024f..0aeb2f88 100644
--- a/tests/checker/__init__.py
+++ b/tests/checker/__init__.py
@@ -67,7 +67,8 @@ class TestLogger (linkcheck.logger._Logger):
             url = u"url %s" % url_data.base_url
             self.result.append(url)
         if self.has_part('cachekey'):
-            self.result.append(u"cache key %s" % url_data.cache_url_key)
+            cache_key = url_data.cache_key[1] if url_data.cache_key else None
+            self.result.append(u"cache key %s" % cache_key)
         if self.has_part('realurl'):
             self.result.append(u"real url %s" % url_data.url)
         if self.has_part('name') and url_data.name:
diff --git a/tests/checker/data/file.html.result b/tests/checker/data/file.html.result
index a43ee61d..167c5fe7 100644
--- a/tests/checker/data/file.html.result
+++ b/tests/checker/data/file.html.result
@@ -4,6 +4,12 @@ real url file://%(curdir)s/%(datadir)s/file.html
 name %(datadir)s/file.html
 valid
 
+url file.html
+cache key file://%(curdir)s/%(datadir)s/file.html
+real url file://%(curdir)s/%(datadir)s/file.html
+name relative url
+valid
+
 url javascript:loadthis()
 cache key javascript:loadthis()
 real url javascript:loadthis()
diff --git a/tests/checker/data/http.html.result b/tests/checker/data/http.html.result
index 27debb66..b3c33b71 100644
--- a/tests/checker/data/http.html.result
+++ b/tests/checker/data/http.html.result
@@ -37,6 +37,11 @@ real url http://localhost:%(port)d/?q=%%C3%%BC
 name html entities
 valid
 
+url 
+cache key http://localhost:%(port)d/tests/checker/data/http.html
+real url http://localhost:%(port)d/tests/checker/data/http.html
+valid
+
 url file.css
 cache key http://localhost:%(port)d/tests/checker/data/file.css
 real url http://localhost:%(port)d/tests/checker/data/file.css
diff --git a/tests/checker/ftpserver.py b/tests/checker/ftpserver.py
index ea35a99b..5e8680fa 100644
--- a/tests/checker/ftpserver.py
+++ b/tests/checker/ftpserver.py
@@ -20,6 +20,7 @@ Define http test support classes for LinkChecker tests.
 import os
 import time
 import threading
+import pytest
 from ftplib import FTP
 from . import LinkCheckTest
 
diff --git a/tests/checker/test_file.py b/tests/checker/test_file.py
index c8fe837a..f5211c49 100644
--- a/tests/checker/test_file.py
+++ b/tests/checker/test_file.py
@@ -145,6 +145,11 @@ class TestFile (LinkCheckTest):
             u"cache key %s" % nurl,
             u"real url %s" % nurl,
             u"valid",
+            u"url bl.html",
+            u"cache key %s" % nurl,
+            u"real url %s" % nurl,
+            u"name link",
+            u"valid",
             u"url el.html",
             u"cache key %s" % nurl2,
             u"real url %s" % nurl2,
diff --git a/tests/checker/test_news.py b/tests/checker/test_news.py
index 00a89e39..95659bde 100644
--- a/tests/checker/test_news.py
+++ b/tests/checker/test_news.py
@@ -30,7 +30,7 @@ NNTP_INFO = u"200 news.uni-stuttgart.de InterNetNews NNRP server " \
 NNTP_TIMEOUT_SECS = 30
 
 # disabled for now until some stable news server comes up
-class TestNews (LinkCheckTest):
+class _TestNews (LinkCheckTest):
     """Test nntp: and news: link checking."""
 
     def newstest (self, url, resultlines):