diff --git a/src/arch/arm/regs/misc_types.hh b/src/arch/arm/regs/misc_types.hh
index e446ce5fd0..e6f7e406f2 100644
--- a/src/arch/arm/regs/misc_types.hh
+++ b/src/arch/arm/regs/misc_types.hh
@@ -123,7 +123,7 @@ namespace ArmISA
         Bitfield<19, 16> crc32;
         Bitfield<15, 12> sha2;
         Bitfield<11, 8> sha1;
-        Bitfield<3, 0> aes;
+        Bitfield<7, 4> aes;
     EndBitUnion(AA64ISAR0)
 
     BitUnion64(AA64ISAR1)