diff --git a/web/redux/actions/notification-actions.js b/web/redux/actions/notification-actions.js
index 6af9480..c0a57b0 100644
--- a/web/redux/actions/notification-actions.js
+++ b/web/redux/actions/notification-actions.js
@@ -40,6 +40,8 @@ export function handleSendNotification(title, body, roomName) {
 
 export function handleMessageUserMentionNotification(message) {
   return (dispatch, getStore) => {
+    const store = getStore();
+    
     // Prop validation
     if (!message.message.mentionedUsernames || !message.message.mentionedUsernames.length) {
       return null;
@@ -49,7 +51,7 @@ export function handleMessageUserMentionNotification(message) {
       return null;
     }
 
-    const authUsername = getStore().getIn(['authUser', 'username'], '').toLowerCase();
+    const authUsername = store.getIn(['authUser', 'username'], '').toLowerCase();
     if (message.user.username.toLowerCase() === authUsername) {
       return null;
     }
@@ -73,6 +75,11 @@ export function handleNewMessageNotification(message) {
       return null;
     }
 
+    const lastSeenRoomTime = store.getIn(['lastSeenTimes', message.room.name]);
+    if (message.message.createDateLongUTC < lastSeenRoomTime) {
+      return null;
+    }
+
     dispatch(handleMessageUserMentionNotification(message));
   };
 }