diff --git a/valve/source/messages.py b/valve/source/messages.py
index d02c5e6..1f11c1c 100644
--- a/valve/source/messages.py
+++ b/valve/source/messages.py
@@ -376,7 +376,7 @@ def decode(self, buffer, values={}):
         return entries_dict, buffer
 
 
-class Message(collections.Mapping):
+class Message(collections.abc.Mapping): # edited
 
     fields = ()