diff -u -r a/vendor/github.com/containerd/btrfs/btrfs.c b/vendor/github.com/containerd/btrfs/btrfs.c
--- a/vendor/github.com/containerd/btrfs/btrfs.c	2025-07-11 22:08:17.013769624 +0200
+++ b/vendor/github.com/containerd/btrfs/btrfs.c	2025-07-11 22:24:52.906525426 +0200
@@ -15,6 +15,7 @@
 */
 
 #include <stddef.h>
+#include <string.h>
 #include <linux/magic.h>
 #include <btrfs/ioctl.h>
 #include <btrfs/ctree.h>