diff --git a/cps/tornado_wsgi.py b/cps/tornado_wsgi.py
index af93219c..cf302042 100644
--- a/cps/tornado_wsgi.py
+++ b/cps/tornado_wsgi.py
@@ -53,7 +53,7 @@ class MyWSGIContainer(WSGIContainer):
             return response.append
 
         app_response = self.wsgi_application(
-            MyWSGIContainer.environ(request), start_response
+            self.environ(request), start_response
         )
         try:
             response.extend(app_response)
@@ -86,9 +86,8 @@ class MyWSGIContainer(WSGIContainer):
         request.connection.finish()
         self._log(status_code, request)
 
-    @staticmethod
-    def environ(request: httputil.HTTPServerRequest) -> Dict[Text, Any]:
-        environ = WSGIContainer.environ(request)
+    def environ(self, request: httputil.HTTPServerRequest) -> Dict[Text, Any]:
+        environ = super().environ(request)
         environ['RAW_URI'] = request.path
         return environ