diff --git a/p9_cfam.hpp b/p9_cfam.hpp
index 0cf5c02..43bbaa5 100644
--- a/p9_cfam.hpp
+++ b/p9_cfam.hpp
@@ -16,8 +16,10 @@
 static constexpr uint16_t P9_FSI2PIB_TRUE_MASK     = 0x100D;
 static constexpr uint16_t P9_CBS_CS                = 0x2801;
 static constexpr uint16_t P9_SBE_CTRL_STATUS       = 0x2808;
+static constexpr uint16_t P9_SBE_MSG_REGISTER      = 0x2809;
 static constexpr uint16_t P9_ROOT_CTRL0            = 0x2810;
 static constexpr uint16_t P9_PERV_CTRL0            = 0x281A;
+static constexpr uint16_t P9_HB_MBX5_REG           = 0x283C;
 static constexpr uint16_t P9_SCRATCH_REGISTER_8    = 0x283F;
 static constexpr uint16_t P9_ROOT_CTRL8            = 0x2918;
 }