diff --git a/files/routes/posts.py b/files/routes/posts.py
index a8ba72047..a2534e9b8 100644
--- a/files/routes/posts.py
+++ b/files/routes/posts.py
@@ -181,12 +181,11 @@ def post_id(pid, anything=None, v=None):
 
 		post.preloaded_comments = [x for x in comments if not (x.author and x.author.shadowbanned) or (v and v.id == x.author_id)]
 
-	if v and v.id == 1: print(session.get("read_comments"))
 	if session.get("read_comments"): read = list(session.get("read_comments"))
 	else: read = None
-	read_comments = [x.id for x in post.preloaded_comments]
-	if read: session["read_comments"] += read_comments
-	else: session["read_comments"] = read_comments
+	read_comments = set([x.id for x in post.preloaded_comments])
+	if read: session["read_comments"].add(read_comments)
+	else: session["read_comments"] = set(read_comments)
 
 	post.views += 1
 	g.db.add(post)