diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index 9223865cb9..aff5c25620 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -216,7 +216,6 @@ private:
     control_mode_t control_mode;
 
     control_mode_t prev_control_mode;
-    ModeReason prev_control_mode_reason = ModeReason::UNKNOWN;
 
 #if RCMAP_ENABLED == ENABLED
     RCMapper rcmap;
diff --git a/ArduSub/flight_mode.cpp b/ArduSub/flight_mode.cpp
index 2fed178399..2801d2cad8 100644
--- a/ArduSub/flight_mode.cpp
+++ b/ArduSub/flight_mode.cpp
@@ -10,7 +10,6 @@ bool Sub::set_mode(control_mode_t mode, ModeReason reason)
     // return immediately if we are already in the desired mode
     if (mode == control_mode) {
         prev_control_mode = control_mode;
-        prev_control_mode_reason = control_mode_reason;
 
         control_mode_reason = reason;
         return true;
@@ -70,7 +69,6 @@ bool Sub::set_mode(control_mode_t mode, ModeReason reason)
         exit_mode(control_mode, mode);
 
         prev_control_mode = control_mode;
-        prev_control_mode_reason = control_mode_reason;
 
         control_mode = mode;
         control_mode_reason = reason;