diff --git a/libraries/AP_L1_Control/AP_L1_Control.cpp b/libraries/AP_L1_Control/AP_L1_Control.cpp
index 369e59e406..45eb86cdbd 100644
--- a/libraries/AP_L1_Control/AP_L1_Control.cpp
+++ b/libraries/AP_L1_Control/AP_L1_Control.cpp
@@ -135,7 +135,6 @@ void AP_L1_Control::_prevent_indecision(float &Nu)
 }
 
 // update L1 control for waypoint navigation
-// this function costs about 3.5 milliseconds on a AVR2560
 void AP_L1_Control::update_waypoint(const struct Location &prev_WP, const struct Location &next_WP)
 {