diff --git a/core/aux.py b/core/aux.py
index 3de5e48..06f4d1e 100644
--- a/core/aux.py
+++ b/core/aux.py
@@ -9,10 +9,10 @@ _print = text.Output('over.core', stream=sys.stderr)
 
 class DeprecationForwarder:
 	def __init__(self, target, old_name, new_name):
-		self.target = target
-		self.old_name = old_name
-		self.new_name = new_name
+		self._target = target
+		self._old_name = old_name
+		self._new_name = new_name
 	
 	def __getattr__(self, name):
-		_print('%s is deprecated, please use %s instead' %(self.old_name, self.new_name), text.prefix.warn)
-		return getattr(self.target, name)
+		_print('%s is deprecated, please use %s instead' %(self._old_name, self._new_name), text.prefix.warn)
+		return getattr(self._target, name)