diff --git a/files/helpers/comments.py b/files/helpers/comments.py
index afd622f5c..42139a90e 100644
--- a/files/helpers/comments.py
+++ b/files/helpers/comments.py
@@ -8,10 +8,17 @@ def update_stateful_counters(comment, delta):
 	When a comment changes publish status, we need to update all affected stateful
 	comment counters (e.g. author comment count, post comment count)
 	"""
+	update_post_comment_count(comment, delta)
+	update_author_comment_count(comment, delta)
+	update_ancestor_descendant_counts(comment, delta)
+
+def update_post_comment_count(comment, delta):
 	author = comment.author
 	comment.post.comment_count += delta
 	g.db.add(comment.post)
 
+def update_author_comment_count(comment, delta):
+	author = comment.author
 	comment.author.comment_count = g.db.query(Comment).filter(
 		Comment.author_id == comment.author_id,
 		Comment.parent_submission != None,
@@ -20,6 +27,14 @@ def update_stateful_counters(comment, delta):
 	).count()
 	g.db.add(comment.author)
 
+def update_ancestor_descendant_counts(comment, delta):
+	parent = comment.parent_comment_writable
+	if parent is None:
+		return
+	parent.descendant_count += delta
+	g.db.add(parent)
+	update_ancestor_descendant_counts(parent, delta)
+
 def comment_on_publish(comment:Comment):
 	"""
 	Run when comment becomes visible: immediately for non-filtered comments,
diff --git a/files/tests/test_child_comment_counts.py b/files/tests/test_child_comment_counts.py
index 77c128118..dda8fb123 100644
--- a/files/tests/test_child_comment_counts.py
+++ b/files/tests/test_child_comment_counts.py
@@ -3,7 +3,7 @@ from . import fixture_submissions
 from . import fixture_comments
 from . import util
 from files.__main__ import db_session
-from files.classes import Submission
+from files.classes import Submission, Comment
 import json
 
 
@@ -84,3 +84,49 @@ def test_submission_comment_count(accounts, submissions, comments):
 	})
 
 	assert 0 == post.comment_count
+
+@util.no_rate_limit
+def test_comment_descendant_count(accounts, submissions, comments):
+	"""
+		Here is a contentious top-level comment
+			You're wrong, this isn't contentious
+				no u
+			Good poast
+	"""
+	db = db_session()
+	alice_client, alice = accounts.client_and_user_for_account('Alice')
+
+	post = submissions.submission_for_client(alice_client, {
+		'title': 'Discussion',
+		'body': 'Discuss stuff',
+	})
+	post_id = post.id
+
+	root = comments.comment_for_client(alice_client, post.id, {
+		'body': 'Here is a contentious top-level comment',
+	})
+
+	assert 0 == db.query(Comment).filter_by(id=root.id).first().descendant_count
+
+	reply1 = comments.comment_for_client(alice_client, post.id, {
+		'body': 'You\'re wrong, this isn\'t contentious',
+		'parent_fullname': f't3_{root.id}',
+		'parent_level': root.level,
+	})
+
+	rereply1 = comments.comment_for_client(alice_client, post.id, {
+		'body': 'no u',
+		'parent_fullname': f't3_{reply1.id}',
+		'parent_level': reply1.level,
+	})
+
+	reply2 = comments.comment_for_client(alice_client, post.id, {
+		'body': 'Good poast',
+		'parent_fullname': f't3_{root.id}',
+		'parent_level': root.level,
+	})
+
+	assert 3 == db.query(Comment).filter_by(id=root.id).first().descendant_count
+	assert 1 == db.query(Comment).filter_by(id=reply1.id).first().descendant_count
+	assert 0 == db.query(Comment).filter_by(id=reply2.id).first().descendant_count
+	assert 0 == db.query(Comment).filter_by(id=rereply1.id).first().descendant_count