diff --git a/libraries/AP_NavEKF3/AP_NavEKF3.cpp b/libraries/AP_NavEKF3/AP_NavEKF3.cpp
index cfd9d16c82..7e8dfadb0e 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3.cpp
@@ -1341,7 +1341,7 @@ uint8_t NavEKF3::getActiveAirspeed() const
     if (core) {
         return core[primary].getActiveAirspeed();
     } else {
-        return 255;
+        return UINT8_MAX;
     }
 }