diff --git a/api/routes/forms.py b/api/routes/forms.py
index f3430ed..0dd0fb7 100644
--- a/api/routes/forms.py
+++ b/api/routes/forms.py
@@ -19,6 +19,9 @@ def fill_form(form: FormFill, db: Session = Depends(get_db)):
     controller = Controller()
     path = controller.fill_form(user_input=form.input_text, fields=fetched_template.fields, pdf_form_path=fetched_template.pdf_path)
 
+    if not path:
+        raise AppError("PDF generation failed", status_code=400)
+
     submission = FormSubmission(**form.model_dump(), output_pdf_path=path)
     return create_form(db, submission)