diff --git a/api4/cloud.go b/api4/cloud.go
index 4957403ac9..a0d3a9b257 100644
--- a/api4/cloud.go
+++ b/api4/cloud.go
@@ -39,7 +39,7 @@ func (api *API) InitCloud() {
 	// GET /api/v4/cloud/subscription
 	api.BaseRoutes.Cloud.Handle("/subscription", api.APISessionRequired(getSubscription)).Methods("GET")
 	api.BaseRoutes.Cloud.Handle("/subscription/invoices", api.APISessionRequired(getInvoicesForSubscription)).Methods("GET")
-	api.BaseRoutes.Cloud.Handle("/subscription/invoices/{invoice_id:[A-Za-z0-9]+}/pdf", api.APISessionRequired(getSubscriptionInvoicePDF)).Methods("GET")
+	api.BaseRoutes.Cloud.Handle("/subscription/invoices/{invoice_id:[_A-Za-z0-9]+}/pdf", api.APISessionRequired(getSubscriptionInvoicePDF)).Methods("GET")
 	api.BaseRoutes.Cloud.Handle("/subscription/expand", api.APISessionRequired(GetLicenseExpandStatus)).Methods("GET")
 	api.BaseRoutes.Cloud.Handle("/subscription", api.APISessionRequired(changeSubscription)).Methods("PUT")