diff --git a/app/services/refinement_test.rb b/app/services/refinement_test.rb
index 957c9662d..fd59a853c 100644
--- a/app/services/refinement_test.rb
+++ b/app/services/refinement_test.rb
@@ -1,7 +1,7 @@
 module RefinementTest
   refine String do
     def formatted_postcode
-      postcode = self.upcase.gsub(/\s+/, "")
+      postcode = upcase.gsub(/\s+/, "")
       case postcode.length
       when 5
         postcode.insert(2, " ")