diff --git a/main.py b/main.py
index f1d551a..e0058bb 100644
--- a/main.py
+++ b/main.py
@@ -428,7 +428,7 @@ def __init__(self, account_name, login, password, tm_api, mafile_name):
                 self.steam_api = self.get_my_steam_api()
                 break
 
-        self.sent_offers_messages = []
+        self.sent_offers_messages = {}
 
         self.run()
 
@@ -600,7 +600,7 @@ def create_offers(self, offers):
             # If session is ok, and trade offer need confirmation
             if response.status_code == 200:
                 message(self.account_name, 'y>', f'Offer #{counter}/{len(offers)} creating..')
-                self.sent_offers_messages.append(offer['tradeoffermessage'])
+                self.sent_offers_messages[offer['tradeoffermessage']] = time()
                 sleep(1)
                 continue