diff --git a/discord/client.py b/discord/client.py
index 8e14e8753..3013c5053 100644
--- a/discord/client.py
+++ b/discord/client.py
@@ -590,7 +590,10 @@ class Client:
         """
 
         def predicate(message):
-            result = message.author == author
+            result = True
+            if author is not None:
+                result = result and message.author == author
+
             if content is not None:
                 result = result and message.content == content