diff --git a/app/models/incoming_email.rb b/app/models/incoming_email.rb
index 9092eb28349..bd77ed8bee5 100644
--- a/app/models/incoming_email.rb
+++ b/app/models/incoming_email.rb
@@ -104,5 +104,6 @@ end
 #  index_incoming_emails_on_imap_sync      (imap_sync)
 #  index_incoming_emails_on_message_id     (message_id)
 #  index_incoming_emails_on_post_id        (post_id)
+#  index_incoming_emails_on_topic_id       (topic_id)
 #  index_incoming_emails_on_user_id        (user_id) WHERE (user_id IS NOT NULL)
 #
diff --git a/db/migrate/20240304030429_topic_id_on_incoming_email_index.rb b/db/migrate/20240304030429_topic_id_on_incoming_email_index.rb
new file mode 100644
index 00000000000..43d378313d5
--- /dev/null
+++ b/db/migrate/20240304030429_topic_id_on_incoming_email_index.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+class TopicIdOnIncomingEmailIndex < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+
+  def change
+    add_index :incoming_emails, :topic_id, algorithm: :concurrently
+  end
+end