diff --git a/util/cbfstool/elf.h b/util/cbfstool/elf.h
index 01af81988a..9ec8c16465 100644
--- a/util/cbfstool/elf.h
+++ b/util/cbfstool/elf.h
@@ -243,6 +243,7 @@ typedef struct
 #define EM_ARC_A5	93		/* ARC Cores Tangent-A5 */
 #define EM_XTENSA	94		/* Tensilica Xtensa Architecture */
 #define EM_NUM		95
+#define EM_AARCH64	183		/* ARM AARCH64 */
 
 /* If it is necessary to assign new unofficial EM_* values, please
    pick large random numbers (0x8523, 0xa7f2, etc.) to minimize the