diff --git a/ArduPlane/mode.cpp b/ArduPlane/mode.cpp
index 0042b3da0b..6ea91d747d 100644
--- a/ArduPlane/mode.cpp
+++ b/ArduPlane/mode.cpp
@@ -59,6 +59,7 @@ bool Mode::enter()
     plane.guided_state.target_heading_type = GUIDED_HEADING_NONE;
     plane.guided_state.target_airspeed_cm = -1; // same as above, although an airspeed of -1 is rare on plane.
     plane.guided_state.target_alt = -1; // same as above, although a target alt of -1 is rare on plane.
+    plane.guided_state.target_alt_time_ms = 0;
     plane.guided_state.last_target_alt = 0;
 #endif