diff --git a/product/DeadlockDebugger/dumper.py b/product/DeadlockDebugger/dumper.py
index d53ac65a1dd95a4ee78db90c095fa9a343ed4abe..40a4f1a37ff433d1ab428500661403e0fd59836d 100644
--- a/product/DeadlockDebugger/dumper.py
+++ b/product/DeadlockDebugger/dumper.py
@@ -23,7 +23,7 @@ ZServer hook to dump a traceback of the running python threads.
 """
 
 import six
-import _thread
+from six.moves import _thread
 from sys import _current_frames
 from six.moves import cStringIO as StringIO
 import traceback
@@ -114,7 +114,7 @@ def match(self, request):
         return 1
     else:
         return 0
-import six
+
 if six.PY2:
   from ZServer.HTTPServer import zhttp_handler
   zhttp_handler.match = match