diff --git a/lib/builder.rb b/lib/builder.rb
index 6d698bd4..e0d88494 100644
--- a/lib/builder.rb
+++ b/lib/builder.rb
@@ -483,6 +483,8 @@ class CustomWizard::Builder
       user_field = pu['user_field']
       key = pu['key']
       
+      return if data[key].blank?
+
       if user_field || custom_field
         custom_fields[user_field || custom_field] = data[key]
       else