diff --git a/p10_cfam.hpp b/p10_cfam.hpp
index a8e47c4..f4882dd 100644
--- a/p10_cfam.hpp
+++ b/p10_cfam.hpp
@@ -8,6 +8,7 @@
 {
 
 static constexpr uint16_t P10_ROOT_CTRL8 = 0x2818;
+static constexpr uint16_t P10_SCRATCH_REG_12 = 0x2983;
 
 } // namespace p10
 } // namespace cfam