diff --git a/src/Miscellaneous/ExpandThread.coffee b/src/Miscellaneous/ExpandThread.coffee
index a31329482..4fd4d44a4 100644
--- a/src/Miscellaneous/ExpandThread.coffee
+++ b/src/Miscellaneous/ExpandThread.coffee
@@ -84,7 +84,7 @@ ExpandThread =
       if post = thread.posts[reply.no]
         nodes.push post.nodes.root
         continue
-      node = Build.postFromObject reply, thread.board
+      node = Build.postFromObject reply, thread.board.ID
       post = new Post node, thread, thread.board
       link = $ 'a[title="Highlight this post"]', node
       link.href = "res/#{thread}#p#{post}"
diff --git a/src/Monitoring/ThreadUpdater.coffee b/src/Monitoring/ThreadUpdater.coffee
index b1c50f2ef..a8ab419e9 100644
--- a/src/Monitoring/ThreadUpdater.coffee
+++ b/src/Monitoring/ThreadUpdater.coffee
@@ -210,7 +210,7 @@ ThreadUpdater =
       continue if num <= ThreadUpdater.lastPost
       # Insert new posts, not older ones.
       count++
-      node = Build.postFromObject postObject, ThreadUpdater.thread.board
+      node = Build.postFromObject postObject, ThreadUpdater.thread.board.ID
       nodes.push node
       posts.push new Post node, ThreadUpdater.thread, ThreadUpdater.thread.board