diff --git a/include/elf.h b/include/elf.h
index 5170f3e2..86e2f0bb 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -687,6 +687,7 @@ typedef struct {
 #define NT_ARM_PACA_KEYS	0x407
 #define NT_ARM_PACG_KEYS	0x408
 #define NT_ARM_TAGGED_ADDR_CTRL	0x409
+#define NT_ARM_PAC_ENABLED_KEYS	0x40a
 #define NT_METAG_CBUF	0x500
 #define NT_METAG_RPIPE	0x501
 #define NT_METAG_TLS	0x502