diff --git a/exosphere/program/source/smc/secmon_smc_rsa.cpp b/exosphere/program/source/smc/secmon_smc_rsa.cpp
index b321d27a1..920a65bea 100644
--- a/exosphere/program/source/smc/secmon_smc_rsa.cpp
+++ b/exosphere/program/source/smc/secmon_smc_rsa.cpp
@@ -33,7 +33,7 @@ namespace ams::secmon::smc {
         struct PrepareEsDeviceUniqueKeyOption {
             using KeyGeneration = util::BitPack32::Field<0,  6, int>;
             using Type          = util::BitPack32::Field<6,  2, EsCommonKeyType>;
-            using Reserved      = util::BitPack32::Field<8, 25, u32>;
+            using Reserved      = util::BitPack32::Field<8, 24, u32>;
         };
 
         constexpr const u8 ModularExponentiateByStorageKeyTable[] = {