diff --git a/modules/simple_forms_api/app/services/simple_forms_api/s3/submission_archiver.rb b/modules/simple_forms_api/app/services/simple_forms_api/s3/submission_archiver.rb
index 96d68deda9c..bb3c169213f 100644
--- a/modules/simple_forms_api/app/services/simple_forms_api/s3/submission_archiver.rb
+++ b/modules/simple_forms_api/app/services/simple_forms_api/s3/submission_archiver.rb
@@ -98,7 +98,7 @@ def fetch_submission_pdf
       end
 
       def submission_pdf_filename
-        @submission_pdf_filename ||= "form_#{submission.form_data['form_number']}.pdf"
+        @submission_pdf_filename ||= "form_#{JSON.parse(submission.form_data)['form_number']}.pdf"
       end
 
       def sign_s3_file_url(pdf)