diff --git a/spec/factories/sales_log.rb b/spec/factories/sales_log.rb
index b98cc6f75..7b0aaa4cd 100644
--- a/spec/factories/sales_log.rb
+++ b/spec/factories/sales_log.rb
@@ -166,6 +166,7 @@ FactoryBot.define do
       has_mscharge { 1 }
       mscharge { 100 }
       mortlen { 10 }
+      mortgage_length_known { 0 }
       pcodenk { 0 }
       postcode_full { "SW1A 1AA" }
       is_la_inferred { false }