diff --git a/app/models/derived_variables/sales_log_variables.rb b/app/models/derived_variables/sales_log_variables.rb
index df9aeb288..05210830b 100644
--- a/app/models/derived_variables/sales_log_variables.rb
+++ b/app/models/derived_variables/sales_log_variables.rb
@@ -53,7 +53,7 @@ module DerivedVariables::SalesLogVariables
       self.address_line2 = nil
       self.town_or_city = nil
       self.county = nil
-      self.postcode_known = nil
+      self.pcodenk = nil
       self.postcode_full = nil
       self.la = nil
     end