diff --git a/lib/tasks/import.rake b/lib/tasks/import.rake
index ed6bdc25ce6..aad8637404c 100644
--- a/lib/tasks/import.rake
+++ b/lib/tasks/import.rake
@@ -22,6 +22,7 @@ task "import:ensure_consistency" => :environment do
   update_users
   update_groups
   update_tag_stats
+  update_topic_users
   create_category_definitions
 
   log "Done!"
@@ -29,6 +30,10 @@ end
 
 MS_SPEND_CREATING_POST ||= 5000
 
+# -- TODO: We need to check the queries are actually adding/updating the necessary
+# data, post migration. The ON CONFLICT DO NOTHING may cause the clauses to be ignored
+# when we actually need them to run.
+
 def insert_post_timings
   log "Inserting post timings..."
 
@@ -415,6 +420,29 @@ def update_tag_stats
   Tag.ensure_consistency!
 end
 
+def update_topic_users
+  log "Updating topic users..."
+
+  DB.exec <<-SQL
+    WITH X AS (
+        SELECT p.topic_id
+             , p.user_id
+          FROM posts p
+          JOIN topics t ON t.id = p.topic_id
+         WHERE p.deleted_at IS NULL
+           AND t.deleted_at IS NULL
+           AND NOT p.hidden
+           AND t.visible
+    )
+    UPDATE topic_users tu
+       SET posted = 't'
+      FROM X
+     WHERE tu.topic_id = X.topic_id
+       AND tu.user_id = X.user_id
+       AND posted = 'f'
+  SQL
+end
+
 def create_category_definitions
   log "Creating category definitions"
   Category.ensure_consistency!