diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index 7cb61aca3797..e070ada06196 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -2259,6 +2259,7 @@ UnsignedEnum	55:52	BBM
 	0b0000	0
 	0b0001	1
 	0b0010	2
+	0b0011	3
 EndEnum
 UnsignedEnum	51:48	TTL
 	0b0000	NI