diff --git a/app/services/invoice/generateInvoice.server.tsx b/app/services/invoice/generateInvoice.server.tsx
index 26a8c22..5445f99 100644
--- a/app/services/invoice/generateInvoice.server.tsx
+++ b/app/services/invoice/generateInvoice.server.tsx
@@ -206,7 +206,7 @@ export function toDraftOrderGid(input: string): string {
 }
 
 function sanitiseForFilename(s: string): string {
-  return s.replace(/[^A-Za-z0-9._-]/g, "_");
+  return s.replace(/[^A-Za-z0-9._-]/g, "");
 }
 
 export { sanitiseForFilename };