diff --git a/libc/kernel/uapi/linux/shm.h b/libc/kernel/uapi/linux/shm.h
index a30a089..57394cb 100644
--- a/libc/kernel/uapi/linux/shm.h
+++ b/libc/kernel/uapi/linux/shm.h
@@ -53,7 +53,9 @@
 #define SHM_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB
 #define SHM_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB
 #define SHM_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB
+#define SHM_HUGE_32MB HUGETLB_FLAG_ENCODE_32MB
 #define SHM_HUGE_256MB HUGETLB_FLAG_ENCODE_256MB
+#define SHM_HUGE_512MB HUGETLB_FLAG_ENCODE_512MB
 #define SHM_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB
 #define SHM_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB
 #define SHM_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB