diff --git a/linkcheck/checker/consumer.py b/linkcheck/checker/consumer.py
index c5763816..7efb4f95 100644
--- a/linkcheck/checker/consumer.py
+++ b/linkcheck/checker/consumer.py
@@ -52,16 +52,16 @@ def print_duration (duration):
     print >> stderr, msg,
 
 
-class Consumer (object):
+class Consumer (threading.Lock):
     """
-    Consume urls from the url queue in a threaded manner. Also supply
-    thread-safe data acquiring methods.
+    Consume urls from the url queue in a thread-safe manner.
     """
 
     def __init__ (self, config, cache):
         """
         Initialize consumer data and threads.
         """
+        super(Consumer, self).__init__()
         self.config = config
         self.cache = cache
         self.threader = linkcheck.threader.Threader()
@@ -69,14 +69,26 @@ class Consumer (object):
         self.logger = config['logger']
         self.fileoutput = config['fileoutput']
         self.linknumber = 0
-        # one lock for the data
-        self.lock = threading.Lock()
         # if checking had errors
         self.errors = False
         # if checking had warnings
         self.warnings = False
         self.logger_start_output()
 
+    def acquire (self):
+        """
+        Acquire lock.
+        """
+        linkcheck.log.debug(linkcheck.LOG_THREAD, "acquire data lock")
+        super(Consumer, self).acquire()
+
+    def release (self):
+        """
+        Release lock.
+        """
+        linkcheck.log.debug(linkcheck.LOG_THREAD, "release data lock")
+        super(Consumer, self).release()
+
     def _set_threads (self, num):
         """
         Set number of checker threads to start.
@@ -136,22 +148,22 @@ class Consumer (object):
         """
         Return True if checking is finished.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             return self.threader.finished() and \
                    self.cache.incoming_len() <= 0
         finally:
-            self.lock.release()
+            self.release()
 
     def no_more_threads (self):
         """
         Return True if no more active threads are running.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             return self.threader.finished()
         finally:
-            self.lock.release()
+            self.release()
 
     def abort (self):
         """
@@ -164,11 +176,11 @@ class Consumer (object):
                "keyboard interrupt; waiting for %d active threads to finish",
                num)
             linkcheck.log.warn(linkcheck.LOG_CHECK, msg, num)
-            self.lock.acquire()
+            self.acquire()
             try:
                 self.threader.finish()
             finally:
-                self.lock.release()
+                self.release()
             time.sleep(2)
         self.logger_end_output()
 
@@ -176,7 +188,7 @@ class Consumer (object):
         """
         Print check status looking at url queues.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             print >> stderr, _("Status:"),
             active = self.threader.active_threads()
@@ -186,25 +198,25 @@ class Consumer (object):
             print_duration(curtime - start_time)
             print >> stderr
         finally:
-            self.lock.release()
+            self.release()
 
     def logger_start_output (self):
         """
         Start output of all configured loggers.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             self.logger.start_output()
             for logger in self.fileoutput:
                 logger.start_output()
         finally:
-            self.lock.release()
+            self.release()
 
     def logger_new_url (self, url_data):
         """
         Send new url to all configured loggers.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             self.linknumber += 1
             do_filter = (self.linknumber % 1000) == 0
@@ -218,7 +230,7 @@ class Consumer (object):
                 for log in self.fileoutput:
                     log.new_url(url_data)
         finally:
-            self.lock.release()
+            self.release()
         # XXX deadlock!
         #if do_filter:
         #    self.filter_queue(self)
@@ -227,33 +239,33 @@ class Consumer (object):
         """
         End output of all configured loggers.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             self.logger.end_output(linknumber=self.linknumber)
             for logger in self.fileoutput:
                 logger.end_output(linknumber=self.linknumber)
         finally:
-            self.lock.release()
+            self.release()
 
     def active_threads (self):
         """
         Return number of active threads.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             return self.threader.active_threads()
         finally:
-            self.lock.release()
+            self.release()
 
     def get_country_name (self, host):
         """
         Return country code for host if found, else None.
         """
-        self.lock.acquire()
+        self.acquire()
         try:
             gi = self.config["geoip"]
             if gi:
                 return linkcheck.checker.geoip.get_country(gi, host)
             return None
         finally:
-            self.lock.release()
+            self.release()