diff --git a/lib/netsuite/records/custom_field_list.rb b/lib/netsuite/records/custom_field_list.rb
index c9b39b142..7adef30de 100644
--- a/lib/netsuite/records/custom_field_list.rb
+++ b/lib/netsuite/records/custom_field_list.rb
@@ -110,7 +110,7 @@ def create_custom_field(reference_id, field_value)
           when field_value.is_a?(Array)
             'MultiSelectCustomFieldRef'
           when field_value.is_a?(Hash)
-          when field_value.is_a?(NetSuite::Records::RecordRef)
+          when field_value.is_a?(NetSuite::Records::CustomRecordRef)
             'SelectCustomFieldRef'
           when field_value.is_a?(DateTime),
                field_value.is_a?(Time),