diff --git a/RangeHTTPServer.py b/RangeHTTPServer.py
index 3819ff4..acd8ce5 100644
--- a/RangeHTTPServer.py
+++ b/RangeHTTPServer.py
@@ -31,6 +31,7 @@
 
 __all__ = ["RangeHTTPRequestHandler"]
 
+from SocketServer import ThreadingMixIn
 import os
 import posixpath
 import BaseHTTPServer
@@ -267,7 +268,9 @@ def guess_type(self, path):
 
 def test(HandlerClass = RangeHTTPRequestHandler,
          ServerClass = BaseHTTPServer.HTTPServer):
-    BaseHTTPServer.test(HandlerClass, ServerClass)
+    class ThreadingServerClass(ThreadingMixIn, ServerClass):
+        pass
+    BaseHTTPServer.test(HandlerClass, ThreadingServerClass)
 
 
 if __name__ == '__main__':