add this forget about it
#config/initializers/ulid_primary_key_defaults.rb module ActiveRecord module ConnectionAdapters class TableDefinition alias_method :original_primary_key, :primary_key
def primary_key(name, type = :bigint, options) if type == :ulid && !options.key?(:default) options[:default] = -> { "gen_ulid()" } end original_primary_key(name, type, options) end end end end