diff --git a/board/forms.py b/board/forms.py
index 1dc56b4..54e94bc 100644
--- a/board/forms.py
+++ b/board/forms.py
@@ -29,7 +29,7 @@ class ReplyForm(PostForm):
 
     class Meta:
         model = Post
-        fields = ["name", "text", "image"]
+        fields = ["name", "text", "bump", "image"]
 
     def __init__(self, *args, op, reply, **kwargs):
         super(ReplyForm, self).__init__(*args, **kwargs)
diff --git a/board/models.py b/board/models.py
index db589f9..c3286cf 100644
--- a/board/models.py
+++ b/board/models.py
@@ -47,6 +47,9 @@ class Board(models.Model):
     # The amount of time that users from the same IP address are allowed to make
     # consecutive posts
     post_cooldown = models.DurationField(default=timedelta(seconds=60))
+    # Auto-sink threshhold. This is the number of replies that a thread can have
+    # before it stops being bumped.
+    autosink = models.IntegerField(default=300)
 
     @property
     def threads(self):
@@ -89,6 +92,9 @@ class Post(models.Model):
         width_field="image_width",
         height_field="image_height",
     )
+    # Bump - if this post is an OP, determines whether the OP can be bumped. If
+    # this post is not an OP, determines whether the thread SHOULD be bumped.
+    bump = models.BooleanField(default=True)
     # Thumbnail
     thumbnail = models.ImageField(upload_to=thumbs_upload, editable=False, null=True)
     # Original image name
@@ -172,8 +178,13 @@ def post_created(sender, instance, created, **kwargs):
     if created:
         if instance.op:
             # Update the bump
-            instance.op.last_bump = timezone.now()
-            instance.op.save()
+            if (
+                instance.bump
+                and instance.op.bump
+                and instance.op.replies.count() < instance.board.autosink
+            ):
+                instance.op.last_bump = timezone.now()
+                instance.op.save()
         else:
             # Prune threads for the board
             instance.board.prune_threads()