diff --git a/libc/kernel/uapi/linux/pidfd.h b/libc/kernel/uapi/linux/pidfd.h
index 082b4a0..9068727 100644
--- a/libc/kernel/uapi/linux/pidfd.h
+++ b/libc/kernel/uapi/linux/pidfd.h
@@ -8,9 +8,21 @@
 #define _UAPI_LINUX_PIDFD_H
 #include <linux/types.h>
 #include <linux/fcntl.h>
+#include <linux/ioctl.h>
 #define PIDFD_NONBLOCK O_NONBLOCK
 #define PIDFD_THREAD O_EXCL
 #define PIDFD_SIGNAL_THREAD (1UL << 0)
 #define PIDFD_SIGNAL_THREAD_GROUP (1UL << 1)
 #define PIDFD_SIGNAL_PROCESS_GROUP (1UL << 2)
+#define PIDFS_IOCTL_MAGIC 0xFF
+#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
+#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
+#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
+#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
+#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
+#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
+#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
+#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
+#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
+#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
 #endif