diff --git a/drivers/xen/xen-pciback/passthrough.c b/drivers/xen/xen-pciback/passthrough.c
index e01e4b6..828dddc 100644
--- a/drivers/xen/xen-pciback/passthrough.c
+++ b/drivers/xen/xen-pciback/passthrough.c
@@ -176,7 +176,7 @@
 	return 1;
 }
 
-struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
+const struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
 	.name           = "passthrough",
 	.init           = __xen_pcibk_init_devices,
 	.free		= __xen_pcibk_release_devices,