diff --git a/libc/kernel/uapi/linux/elf.h b/libc/kernel/uapi/linux/elf.h
index 428da63..f9f122a 100644
--- a/libc/kernel/uapi/linux/elf.h
+++ b/libc/kernel/uapi/linux/elf.h
@@ -359,6 +359,7 @@
 #define NT_ARM_PAC_MASK 0x406
 #define NT_ARM_PACA_KEYS 0x407
 #define NT_ARM_PACG_KEYS 0x408
+#define NT_ARM_TAGGED_ADDR_CTRL 0x409
 #define NT_ARC_V2 0x600
 #define NT_VMCOREDD 0x700
 #define NT_MIPS_DSP 0x800