diff --git a/VERSION b/VERSION
index 8009008d..de0cdbc9 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-Version 2.00.1 (2012-08-29 08:22:30) rc4
+Version 2.00.1 (2012-08-29 10:05:45) rc4
diff --git a/gluon/http.py b/gluon/http.py
index 5963603a..69356b85 100644
--- a/gluon/http.py
+++ b/gluon/http.py
@@ -76,7 +76,8 @@ class HTTP(BaseException):
             self.headers['Set-Cookie'] = [
                 str(cookie)[11:] for cookie in cookies.values()]
 
-    def to(self, responder, env={}):
+    def to(self, responder, env=None):
+        env = env or {}
         status = self.status
         headers = self.headers
         if status in defined_status: