diff --git a/ptulsconv/pdf/__init__.py b/ptulsconv/pdf/__init__.py
index 4dfe528..d9ca587 100644
--- a/ptulsconv/pdf/__init__.py
+++ b/ptulsconv/pdf/__init__.py
@@ -72,12 +72,12 @@ def make_doc_template(page_size, filename, document_title,
     header_box, page_box = page_box.split_y(0.75 * inch, direction='d')
     title_box, report_box = header_box.split_x(3.5 * inch, direction='r')
     
-    on_page_lambda = lambda c, _: 
+    on_page_lambda = (lambda c, _: 
         draw_header_footer(c, report_box, title_box, 
         footer_box,title=title, 
         supervisor=supervisor,     
         document_subheader=document_subheader, 
-        client=client, doc_title=document_header)
+        client=client, doc_title=document_header))
     
     frames = [Frame(page_box.min_x, page_box.min_y, page_box.width, page_box.height)]