diff --git a/libc/kernel/uapi/linux/falloc.h b/libc/kernel/uapi/linux/falloc.h
index fb734e0..54fb5d1 100644
--- a/libc/kernel/uapi/linux/falloc.h
+++ b/libc/kernel/uapi/linux/falloc.h
@@ -26,4 +26,5 @@
 #define FALLOC_FL_ZERO_RANGE 0x10
 #define FALLOC_FL_INSERT_RANGE 0x20
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define FALLOC_FL_UNSHARE_RANGE 0x40
 #endif