diff --git a/libraries/AP_Mission/AP_Mission.cpp b/libraries/AP_Mission/AP_Mission.cpp
index f15e753e4a031..89691085d3b51 100644
--- a/libraries/AP_Mission/AP_Mission.cpp
+++ b/libraries/AP_Mission/AP_Mission.cpp
@@ -2553,7 +2553,7 @@ bool AP_Mission::distance_to_landing(uint16_t index, float &tot_distance, Locati
     }
 
     // run through remainder of mission to approximate a distance to landing
-    for (uint8_t i=0; i<255; i++) {
+    for (uint8_t i=0; i<UINT8_MAX; i++) {
         // search until the end of the mission command list
         for (uint16_t cmd_index = index; cmd_index < (unsigned)_cmd_total; cmd_index++) {
             // get next command
@@ -2612,7 +2612,7 @@ bool AP_Mission::distance_to_mission_leg(uint16_t start_index, float &rejoin_dis
 
     // run through remainder of mission to approximate a distance to landing
     uint16_t index = start_index;
-    for (uint8_t i=0; i<255; i++) {
+    for (uint8_t i=0; i<UINT8_MAX; i++) {
         // search until the end of the mission command list
         for (uint16_t cmd_index = index; cmd_index <= (unsigned)_cmd_total; cmd_index++) {
             if (get_next_cmd(cmd_index, temp_cmd, true, false)) {