diff --git a/sys/dev/virtio/gpu/virtio_gpu.c b/sys/dev/virtio/gpu/virtio_gpu.c
index 0009d7bb3ec..f18eef985cc 100644
--- a/sys/dev/virtio/gpu/virtio_gpu.c
+++ b/sys/dev/virtio/gpu/virtio_gpu.c
@@ -565,7 +565,7 @@ vtgpu_attach_backing(struct vtgpu_softc *sc)
 	s.req.backing.resource_id = htole32(VTGPU_RESOURCE_ID);
 	s.req.backing.nr_entries = htole32(1);
 
-	s.req.mem[0].addr = htole32(sc->vtgpu_fb_info.fb_pbase);
+	s.req.mem[0].addr = htole64(sc->vtgpu_fb_info.fb_pbase);
 	s.req.mem[0].length = htole32(sc->vtgpu_fb_info.fb_size);
 
 	error = vtgpu_req_resp(sc, &s.req, sizeof(s.req), &s.resp,