diff --git a/src/main/java/eu/siacs/conversations/services/NotificationService.java b/src/main/java/eu/siacs/conversations/services/NotificationService.java
index b32e2cb6f..d8d959ee5 100644
--- a/src/main/java/eu/siacs/conversations/services/NotificationService.java
+++ b/src/main/java/eu/siacs/conversations/services/NotificationService.java
@@ -951,7 +951,11 @@ public class NotificationService {
             return false;
         }
 
-        long lastNotificationTimestamp = ensureLastNotificationTimeByConversation().getLong(conversation.getUuid(), 0L);
+        long lastNotificationTimestamp = ensureLastNotificationTimeByConversation().getLong(conversation.getUuid(), -1L);
+
+        if (lastNotificationTimestamp <= 0L) {
+            return false;
+        }
 
         return (System.currentTimeMillis() - lastNotificationTimestamp) < throttlingPeriod;
     }