diff --git a/libc/kernel/uapi/linux/memfd.h b/libc/kernel/uapi/linux/memfd.h
index d3d08a1..e3e5cd5 100644
--- a/libc/kernel/uapi/linux/memfd.h
+++ b/libc/kernel/uapi/linux/memfd.h
@@ -18,6 +18,20 @@
  ****************************************************************************/
 #ifndef _UAPI_LINUX_MEMFD_H
 #define _UAPI_LINUX_MEMFD_H
+#include <asm-generic/hugetlb_encode.h>
 #define MFD_CLOEXEC 0x0001U
 #define MFD_ALLOW_SEALING 0x0002U
+#define MFD_HUGETLB 0x0004U
+#define MFD_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT
+#define MFD_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK
+#define MFD_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB
+#define MFD_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB
+#define MFD_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB
+#define MFD_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB
+#define MFD_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB
+#define MFD_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB
+#define MFD_HUGE_256MB HUGETLB_FLAG_ENCODE_256MB
+#define MFD_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB
+#define MFD_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB
+#define MFD_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB
 #endif