diff --git a/frappe/chat/doctype/chat_room/chat_room.py b/frappe/chat/doctype/chat_room/chat_room.py
index b5873fa2d0..d0085bfab5 100644
--- a/frappe/chat/doctype/chat_room/chat_room.py
+++ b/frappe/chat/doctype/chat_room/chat_room.py
@@ -73,8 +73,11 @@ class ChatRoom(Document):
 		if not self.is_new():
 			before = self.get_doc_before_save()
 			after  = self
+			diff = None
+
+			if before:
+				diff = dictify(get_diff(before, after))
 
-			diff   = dictify(get_diff(before, after))
 			if diff:
 				update = { }
 				for changed in diff.changed: