diff --git a/boards/admin.py b/boards/admin.py
--- a/boards/admin.py
+++ b/boards/admin.py
@@ -1,6 +1,7 @@
 from django.contrib import admin
 from django.utils.translation import ugettext_lazy as _
 from django.core.urlresolvers import reverse
+from django.db.models import F
 from boards.models import Post, Tag, Ban, Thread, Banner, PostImage, KeyPair, GlobalId
 
 
@@ -12,7 +13,8 @@ class PostAdmin(admin.ModelAdmin):
     search_fields = ('id', 'title', 'text', 'poster_ip')
     exclude = ('referenced_posts', 'refmap', 'images', 'global_id')
     readonly_fields = ('poster_ip', 'threads', 'thread', 'linked_images',
-            'attachments', 'uid', 'url', 'pub_time', 'opening', 'linked_global_id')
+            'attachments', 'uid', 'url', 'pub_time', 'opening', 'linked_global_id',
+            'version')
 
     def ban_poster(self, request, queryset):
         bans = 0
@@ -54,6 +56,11 @@ class PostAdmin(admin.ModelAdmin):
                         args=[global_id.id]), str(global_id))
     linked_global_id.allow_tags = True
 
+    def save_model(self, request, obj, form, change):
+        obj.increment_version()
+        obj.save()
+        obj.clear_cache()
+
     actions = ['ban_poster', 'ban_with_hiding']
 
 
@@ -96,6 +103,14 @@ class ThreadAdmin(admin.ModelAdmin):
     def save_related(self, request, form, formsets, change):
         super().save_related(request, form, formsets, change)
         form.instance.refresh_tags()
+
+    def save_model(self, request, obj, form, change):
+        op = obj.get_opening_post()
+        op.increment_version()
+        op.save(update_fields=['version'])
+        obj.save()
+        op.clear_cache()
+
     list_display = ('id', 'op', 'title', 'reply_count', 'status', 'ip',
             'display_tags')
     list_filter = ('bump_time', 'status')
diff --git a/boards/migrations/0045_post_version.py b/boards/migrations/0045_post_version.py
new file mode 100644
--- /dev/null
+++ b/boards/migrations/0045_post_version.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.5 on 2016-05-11 09:23
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('boards', '0044_globalid_content'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='post',
+            name='version',
+            field=models.IntegerField(default=1),
+        ),
+    ]
diff --git a/boards/models/post/__init__.py b/boards/models/post/__init__.py
--- a/boards/models/post/__init__.py
+++ b/boards/models/post/__init__.py
@@ -11,7 +11,7 @@ from boards.utils import datetime_to_epo
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.urlresolvers import reverse
 from django.db import models
-from django.db.models import TextField, QuerySet
+from django.db.models import TextField, QuerySet, F
 from django.template.defaultfilters import truncatewords, striptags
 from django.template.loader import render_to_string
 
@@ -104,6 +104,7 @@ class Post(models.Model, Viewable):
     tripcode = models.CharField(max_length=50, blank=True, default='')
     opening = models.BooleanField(db_index=True)
     hidden = models.BooleanField(default=False)
+    version = models.IntegerField(default=1)
 
     def __str__(self):
         return 'P#{}/{}'.format(self.id, self.get_title())
@@ -379,3 +380,14 @@ class Post(models.Model, Viewable):
 
     def set_hidden(self, hidden):
         self.hidden = hidden
+
+    def increment_version(self):
+        self.version = F('version') + 1
+
+    def clear_cache(self):
+        global_id = self.global_id
+        if global_id is not None and global_id.is_local()\
+                and global_id.content is not None:
+            global_id.content = None
+            global_id.save()
+            global_id.signature_set.all().delete()
diff --git a/boards/models/post/sync.py b/boards/models/post/sync.py
--- a/boards/models/post/sync.py
+++ b/boards/models/post/sync.py
@@ -32,6 +32,7 @@ TAG_TAG = 'tag'
 TAG_ATTACHMENT_REFS = 'attachment-refs'
 TAG_ATTACHMENT_REF = 'attachment-ref'
 TAG_TRIPCODE = 'tripcode'
+TAG_VERSION = 'version'
 
 TYPE_GET = 'get'
 
@@ -126,6 +127,8 @@ class SyncManager:
                         SyncManager._attachment_to_xml(
                             attachments_tag, attachment_refs, file.file.file,
                             file.hash, file.file.url)
+                version_tag = et.SubElement(content_tag, TAG_VERSION)
+                version_tag.text = str(post.version)
 
                 global_id.content = et.tostring(content_tag, ENCODING_UNICODE)
                 global_id.save()