diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
index 5c52b55..e51e7cb 100644
--- a/include/xen/platform_pci.h
+++ b/include/xen/platform_pci.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_PLATFORM_PCI_H
 #define _XEN_PLATFORM_PCI_H