diff --git a/db/migrate/20200629020618_add_sync_num_to_mirrors.rb b/db/migrate/20200629020618_add_sync_num_to_mirrors.rb
new file mode 100644
index 000000000..2e80687f9
--- /dev/null
+++ b/db/migrate/20200629020618_add_sync_num_to_mirrors.rb
@@ -0,0 +1,5 @@
+class AddSyncNumToMirrors < ActiveRecord::Migration[5.2]
+  def change
+    add_column :mirrors, :sync_num, :integer, default: 1
+  end
+end