diff --git a/src/twitter.py b/src/twitter.py
index fd5fd83..54648b7 100644
--- a/src/twitter.py
+++ b/src/twitter.py
@@ -26,7 +26,8 @@ def check_new_tweets(tweets, list_id):
             new_tweets.append(tweet)
     
     LATEST_TWEET_ID_DICT[list_id] = tweets[0]["rest_id"]
-    LATEST_TWEET_TS_DICT[list_id] = tweets[0]["timestamp"]
+    if tweets[0]["timestamp"] > LATEST_TWEET_TS_DICT.get(list_id, 0):
+        LATEST_TWEET_TS_DICT[list_id] = tweets[0]["timestamp"]
     return new_tweets