diff --git a/library/SIMTRACE_Types.ttcn b/library/SIMTRACE_Types.ttcn
index 7b1c857..d28df2f 100644
--- a/library/SIMTRACE_Types.ttcn
+++ b/library/SIMTRACE_Types.ttcn
@@ -273,7 +273,8 @@
 };
 
 type record CardEmu_BD_Config {
-	CardEmu_FeatureFlags	features
+	CardEmu_FeatureFlags	features,
+	uint8_t			slot_mux_nr optional
 };
 
 /***********************************************************************