diff --git a/app/models.py b/app/models.py
index 731c576..9ae3001 100644
--- a/app/models.py
+++ b/app/models.py
@@ -117,6 +117,24 @@ class Users(Model):
     def is_subscribed(self, thread_id):
         return Subscriptions.count({'user_id': self.id, 'thread_id': thread_id}) > 0
 
+    def get_unread_count(self):
+        q = """
+            SELECT
+                COUNT(posts.id) as c
+            FROM
+                subscriptions
+            JOIN
+                threads ON subscriptions.thread_id = threads.id
+            JOIN
+                posts ON threads.id = posts.thread_id
+            WHERE
+                subscriptions.user_id = ?
+            AND
+                posts.created_at > subscriptions.last_seen
+        """
+        res = db.fetch_one(q, self.id)
+        return res["c"] or 0
+
 
 class Topics(Model):
     table = 'topics'
diff --git a/app/routes/threads.py b/app/routes/threads.py
index 13af218..a0d0f9d 100644
--- a/app/routes/threads.py
+++ b/app/routes/threads.py
@@ -1,6 +1,6 @@
 from flask import Blueprint, redirect, url_for, render_template, request, abort
 from functools import wraps
-from ..auth import login_required, get_active_user
+from ..auth import login_required, get_active_user, is_logged_in
 from ..models import Threads, Posts, Topics, Users, Reactions, Subscriptions
 from ..util import get_form_checkbox, time_now
 import math
@@ -59,6 +59,11 @@ def thread(thread_id, slug):
             abort(404)
     posts = thread.get_posts(PER_PAGE, page)
     last_post = posts[-1]
+    user = get_active_user()
+    if user:
+        subscription = Subscriptions.find({'user_id': user.id, 'thread_id': thread.id})
+        if subscription:
+            subscription.update({'last_seen': last_post['created_at']})
     return render_template(
         'threads/thread.html', thread=thread,
         posts=posts, page=page,
diff --git a/app/templates/common/topnav.html b/app/templates/common/topnav.html
index f80a4fa..90b6d99 100644
--- a/app/templates/common/topnav.html
+++ b/app/templates/common/topnav.html
@@ -3,10 +3,11 @@
   <span>anti-social media</span>
   {%- if is_logged_in() -%}
   {%- with user = get_active_user() -%}
+  {%- set uc = user.get_unread_count() -%}
   <ul class="horizontal wrap">
     <li class="mobile-fill-flex">Welcome, <a href="{{url_for('users.user_page', username=user.username)}}">{{ user.get_readable_name() }}</a></li>
     <li><a class="linkbutton" href="{{url_for('users.settings', username=user.username)}}">Settings</a></li>
-    <li><a class="linkbutton" href="{{url_for('users.inbox', username=user.username)}}">Inbox</a></li>
+    <li><a class="linkbutton" href="{{url_for('users.inbox', username=user.username)}}">Inbox{{' (%s)' % uc if uc else ''}}</a></li>
     <li><a class="linkbutton" href="{{url_for('users.bookmarks', username=user.username)}}">Bookmarks</a></li>
     {% if user.is_mod() -%}
     <li><a class="linkbutton" href="{{url_for('mod.index')}}">Moderation</a></li>