diff --git a/boards/templates/boards/post.html b/boards/templates/boards/post.html
--- a/boards/templates/boards/post.html
+++ b/boards/templates/boards/post.html
@@ -5,6 +5,8 @@
 {% get_current_language as LANGUAGE_CODE %}
 
 {% cache 600 post post.id thread.last_edit_time truncated moderator LANGUAGE_CODE need_open_link %}
+
+    {% with is_opening=post.is_opening %}
     {% spaceless %}
         {% with thread=post.thread_new %}
             {% if thread.archived %}
@@ -32,8 +34,10 @@
         <div class="message">
             <div class="post-info">
                 <span class="title">{{ post.title }}</span>
-                <a class="post_id" href="{% post_url post.id %}">
-                    ({{ post.id }}) </a>
+                {% cache 600 post_id post.id %}
+                    <a class="post_id" href="{% post_url post.id %}">
+                        ({{ post.id }}) </a>
+                {% endcache %}
                 [<span class="pub_time">{{ post.pub_time }}</span>]
                 {% if thread.archived %}
                     — [{{ thread.bump_time }}]
@@ -42,7 +46,7 @@
                     [<a href="#" onclick="javascript:addQuickReply('{{ post.id }}')
                         ; return false;">&gt;&gt;</a>]
                 {% endif %}
-                {% if post.is_opening and need_open_link %}
+                {% if is_opening and need_open_link %}
                     {% if post.thread_new.archived %}
                         [<a class="link" href="{% url 'thread' post.id %}">{% trans "Open" %}</a>]
                     {% else %}
@@ -70,20 +74,20 @@
                 {% endif %}
             {% endautoescape %}
             {% cache 600 post_replies post.id post.last_edit_time moderator LANGUAGE_CODE %}
-            {% if post.is_referenced %}
-                <div class="refmap">
-                    {% trans "Replies" %}:
-                    {% for ref_post in post.get_sorted_referenced_posts %}
-                        <a href="{% post_url ref_post.id %}">&gt;&gt;{{ ref_post.id }}</a
-                                >{% if not forloop.last %},{% endif %}
-                    {% endfor %}
-                </div>
-            {% endif %}
+                {% if post.is_referenced %}
+                    <div class="refmap">
+                        {% trans "Replies" %}:
+                        {% for ref_post in post.get_sorted_referenced_posts %}
+                            <a href="{% post_url ref_post.id %}">&gt;&gt;{{ ref_post.id }}</a
+                                    >{% if not forloop.last %},{% endif %}
+                        {% endfor %}
+                    </div>
+                {% endif %}
             {% endcache %}
         </div>
-        {% if post.is_opening and thread.tags.exists %}
+        {% if is_opening and thread.tags.exists %}
             <div class="metadata">
-                {% if post.is_opening and need_open_link %}
+                {% if is_opening and need_open_link %}
                     {{ thread.get_images_count }} {% trans 'images' %}.
                 {% endif %}
                 <span class="tags">
@@ -97,4 +101,5 @@
         </div>
         {% endwith %}
     {% endspaceless %}
+    {% endwith %}
 {% endcache %}
diff --git a/boards/templatetags/board.py b/boards/templatetags/board.py
--- a/boards/templatetags/board.py
+++ b/boards/templatetags/board.py
@@ -73,4 +73,4 @@ def post_view_truncated(post, need_open_
         'truncated': True,
         'need_open_link': need_open_link,
         'moderator': moderator,
-    }
\ No newline at end of file
+    }