diff --git a/ArduPlane/quadplane.cpp b/ArduPlane/quadplane.cpp
index 9557637af4..cf51a68838 100644
--- a/ArduPlane/quadplane.cpp
+++ b/ArduPlane/quadplane.cpp
@@ -33,7 +33,7 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @DisplayName: Transition time
     // @Description: Transition time in milliseconds after minimum airspeed is reached
     // @Units: ms
-    // @Range: 1 30000
+    // @Range: 2000 30000
     // @User: Advanced
     AP_GROUPINFO("TRANSITION_MS", 11, QuadPlane, transition_time_ms, 5000),
 
@@ -1699,14 +1699,15 @@ void SLT_Transition::update()
         // after airspeed is reached we degrade throttle over the
         // transition time, but continue to stabilize
         const uint32_t transition_timer_ms = now - transition_low_airspeed_ms;
-        if (transition_timer_ms > (unsigned)quadplane.transition_time_ms) {
+        const float trans_time_ms = constrain_float(quadplane.transition_time_ms,2000,30000);
+        if (transition_timer_ms > unsigned(trans_time_ms)) {
             transition_state = TRANSITION_DONE;
             in_forced_transition = false;
             transition_start_ms = 0;
             transition_low_airspeed_ms = 0;
             gcs().send_text(MAV_SEVERITY_INFO, "Transition done");
         }
-        float trans_time_ms = MAX((float)quadplane.transition_time_ms.get(),1);
+
         float transition_scale = (trans_time_ms - transition_timer_ms) / trans_time_ms;
         float throttle_scaled = last_throttle * transition_scale;