diff --git a/src/milla/vary.py b/src/milla/vary.py
index 1c87f50..19d0e6f 100644
--- a/src/milla/vary.py
+++ b/src/milla/vary.py
@@ -62,7 +62,7 @@ class VariedResponseMeta(type):
 
 
 _VariedResponseBase = VariedResponseMeta(
-    'VariedResponseBase', (milla.Response,), {})
+    '_VariedResponseBase', (milla.Response,), {})
 
 
 class VariedResponseBase(_VariedResponseBase):