diff --git a/werkzeug/serving.py b/werkzeug/serving.py
index <HASH>..<HASH> 100644
--- a/werkzeug/serving.py
+++ b/werkzeug/serving.py
@@ -69,6 +69,7 @@ class BaseRequestHandler(BaseHTTPRequestHandler, object):
             'wsgi.multithread':     self.server.multithread,
             'wsgi.multiprocess':    self.server.multiprocess,
             'wsgi.run_once':        False,
+            'SERVER_SOFTWARE':      self.server_version,
             'REQUEST_METHOD':       self.command,
             'SCRIPT_NAME':          '',
             'PATH_INFO':            unquote(path_info),
Server now sets the `SERVER_SOFTWARE` environment key.