diff --git a/lib/tasks/new_core.rake b/lib/tasks/new_core.rake
new file mode 100644
index 000000000..f61689b96
--- /dev/null
+++ b/lib/tasks/new_core.rake
@@ -0,0 +1,17 @@
+namespace :new_core do
+  desc 'Sets bs_id field for all BuildList which use new_core'
+  task :update_bs_id => :environment do
+    say "[#{Time.zone.now}] Starting to update bs_id..."
+
+    BuildList.select(:id).
+      where(:new_core => true, :bs_id => nil).
+      find_in_batches(:batch_size => 500) do | bls |
+
+      puts "[#{Time.zone.now}] - where build_lists.id from #{bls.first.id} to #{bls.last.id}"
+      BuildList.where(:id => bls.map(&:id), :bs_id => nil).
+        update_all("bs_id = id")
+    end
+
+    say "[#{Time.zone.now}] done"
+  end
+end
\ No newline at end of file