diff --git a/libc/kernel/uapi/linux/mman.h b/libc/kernel/uapi/linux/mman.h
index 0c9c397..e469374 100644
--- a/libc/kernel/uapi/linux/mman.h
+++ b/libc/kernel/uapi/linux/mman.h
@@ -25,6 +25,9 @@
 #define OVERCOMMIT_GUESS 0
 #define OVERCOMMIT_ALWAYS 1
 #define OVERCOMMIT_NEVER 2
+#define MAP_SHARED 0x01
+#define MAP_PRIVATE 0x02
+#define MAP_SHARED_VALIDATE 0x03
 #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT
 #define MAP_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK
 #define MAP_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB