Lets not waste a perfectly good assignment.

builds/4chan-X.user.js

@@ -9581,7 +9581,7 @@
         if (ID <= Unread.lastReadPost || post.isHidden || QR.db.get({
           boardID: post.board.ID,
           threadID: post.thread.ID,
-          postID: post.ID
+          postID: ID
         })) {
           continue;
         }

builds/crx/script.js

@@ -9564,7 +9564,7 @@
         if (ID <= Unread.lastReadPost || post.isHidden || QR.db.get({
           boardID: post.board.ID,
           threadID: post.thread.ID,
-          postID: post.ID
+          postID: ID
         })) {
           continue;
         }

src/Monitoring/Unread.coffee

@@ -73,7 +73,7 @@ Unread =
       continue if ID <= Unread.lastReadPost or post.isHidden or QR.db.get {
         boardID:  post.board.ID
         threadID: post.thread.ID
-        postID:   post.ID
+        postID:   ID
       }
       Unread.posts.push post unless post.prev or post.next
       Unread.addPostQuotingYou post