diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
index 6abd783..d14b289 100644
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -403,7 +403,9 @@
     VugDev *gdev;
     VubDev *vdev_blk;
 
-    g_return_val_if_fail(len <= sizeof(struct virtio_blk_config), -1);
+    if (len > sizeof(struct virtio_blk_config)) {
+        return -1;
+    }
 
     gdev = container_of(vu_dev, VugDev, parent);
     vdev_blk = container_of(gdev, VubDev, parent);