diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index cfe0633..fa6355a 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -564,7 +564,7 @@
 
 	vma->vm_ops = &gntdev_vmops;
 
-	vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND;
+	vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND|VM_PFNMAP;
 
 	vma->vm_private_data = map;
 	map->vma = vma;