diff --git a/examples/example_config.py b/examples/example_config.py
index 89599f4c..b942f09b 100644
--- a/examples/example_config.py
+++ b/examples/example_config.py
@@ -70,7 +70,7 @@ backlog = 2048
 #       A positive integer. Generally set in the 1-5 seconds range.
 #
 
-workers = 1
+workers = 4
 worker_class = 'sync'
 worker_connections = 1000
 timeout = 30
diff --git a/gunicorn/workers/gtornado.py b/gunicorn/workers/gtornado.py
index 53c51ac4..2337991b 100644
--- a/gunicorn/workers/gtornado.py
+++ b/gunicorn/workers/gtornado.py
@@ -27,7 +27,8 @@ class TornadoWorker(Worker):
 
         def clear(self):
             old_clear(self)
-            self._headers["Server"] += " (Gunicorn/%s)" % gversion
+            if not "Gunicorn" in self._headers["Server"]:
+                self._headers["Server"] += " (Gunicorn/%s)" % gversion
         web.RequestHandler.clear = clear
         sys.modules["tornado.web"] = web