diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index e0bf6c5..8807a2f 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -654,6 +654,9 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 
         id = qemu_get_be32(f);
         port = find_port_by_id(s, id);
+        if (!port) {
+            return -EINVAL;
+        }
 
         port->guest_connected = qemu_get_byte(f);
         host_connected = qemu_get_byte(f);