diff --git a/pdf_renamer.py b/pdf_renamer.py
index b00f792..04ee2ed 100644
--- a/pdf_renamer.py
+++ b/pdf_renamer.py
@@ -429,7 +429,7 @@ def extract_names_from_pdf(pdf_path):
 
             if extracted_data and all(extracted_data.values()):
                 return {
-                    'filename': f"{extracted_data['last_name']}{extracted_data['first_name']}_{extracted_data['grade']}.pdf",
+                    'filename': f"{extracted_data['last_name']}_{extracted_data['first_name']}_{extracted_data['grade']}.pdf",
                     'last_name': extracted_data['last_name'],
                     'first_name': extracted_data['first_name'],
                     'grade': extracted_data['grade'],