diff --git a/Lib/wsgiref/handlers.py b/Lib/wsgiref/handlers.py
index fcb8e23..a5f7109 100644
--- a/Lib/wsgiref/handlers.py
+++ b/Lib/wsgiref/handlers.py
@@ -434,6 +434,10 @@
     """
 
     wsgi_run_once = True
+    # Do not allow os.environ to leak between requests in Google App Engine
+    # and other multi-run CGI use cases.  This is not easily testable.
+    # See http://bugs.python.org/issue7250
+    os_environ = {}
 
     def __init__(self):
         BaseCGIHandler.__init__(