diff --git a/include/membership.php b/include/membership.php
index 97eef72..fcac109 100644
--- a/include/membership.php
+++ b/include/membership.php
@@ -131,7 +131,7 @@ class Membership extends Renderer {
         }
     }
    
-    protected function createPdf(array $formData): TCPDF
+    protected function createPdf(array $formData): string
     {
         $pdf = new Fpdi();
         $pdf->AddFont('DejaVuSans', '', 'DejaVuSans.php');