diff --git a/notify.py b/notify.py
index 8775905..46041b7 100755
--- a/notify.py
+++ b/notify.py
@@ -1,16 +1,45 @@
 #!/usr/bin/env python
 
-import berserk, subprocess
+import berserk, subprocess, pickle
+from os import path
 
 # Change ACCESS TOKEN according to your need
 ACCESS_TOKEN=""
-NOTIFY_DURATION=5*60 # Notification duration in seconds
+NOTIFY_DURATION=15*60 # Notification duration in seconds
+CACHE_FILE="/tmp/lichess_notify_cache" # Change this according to your needs
 
 # Notify using notify-send
 def notify_send(summary, message):
     subprocess.Popen(['notify-send', '-u', 'critical','-t', str(NOTIFY_DURATION*1000), summary, message])
     return
 
+
+# Check if notify already done
+def notify_done(key):
+    if not(path.exists(CACHE_FILE)):
+        return(False)
+    else:
+        with open(CACHE_FILE, 'rb') as f:
+            keys=pickle.load(f)
+            return(key in keys)
+
+# Save notify key in cache
+def add_key(key):
+    if not(path.exists(CACHE_FILE)):
+        with open(CACHE_FILE, 'wb') as f:
+            pickle.dump([key],f)
+            f.close()
+    else:
+        keys=list()
+        with open(CACHE_FILE, 'rb') as f:
+            keys=pickle.load(f)
+            f.close()
+        if not(key in keys):
+            keys.append(key)
+        with open(CACHE_FILE, 'wb') as f:
+            pickle.dump(keys,f)
+            f.close()
+
 # Fetch data and notify
 session = berserk.TokenSession(ACCESS_TOKEN)
 client = berserk.Client(session=session)
@@ -18,6 +47,9 @@ data=client.games.get_ongoing()
 for game in data:
     opponent=game["opponent"]["username"]
     lastMove=game["lastMove"]
+    key=opponent+lastMove
     if game["isMyTurn"]:
-        notify_send("Lichess.org ("+opponent+")","It is your turn !\n Your opponent played "+lastMove)
+        if not(notify_done(key)):
+            notify_send("Lichess.org ("+opponent+")","It is your turn !\n Your opponent played "+lastMove)
+            add_key(key)