diff --git a/libc/kernel/uapi/linux/acct.h b/libc/kernel/uapi/linux/acct.h
index aecc9f6..ba9d25f 100644
--- a/libc/kernel/uapi/linux/acct.h
+++ b/libc/kernel/uapi/linux/acct.h
@@ -74,6 +74,7 @@
 #define ACOMPAT 0x04
 #define ACORE 0x08
 #define AXSIG 0x10
+#define AGROUP 0x20
 #if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
 #define ACCT_BYTEORDER 0x80
 #elif defined(__BYTE_ORDER)?__BYTE_ORDER==__LITTLE_ENDIAN:defined(__LITTLE_ENDIAN)