diff --git a/libraries/AP_Soaring/AP_Soaring.h b/libraries/AP_Soaring/AP_Soaring.h
index 4d13ef8e79..f9dd8b17c8 100644
--- a/libraries/AP_Soaring/AP_Soaring.h
+++ b/libraries/AP_Soaring/AP_Soaring.h
@@ -23,10 +23,10 @@
 #include "Variometer.h"
 #include "SpeedToFly.h"
 
-#define INITIAL_THERMAL_RADIUS 80.0
-#define INITIAL_STRENGTH_COVARIANCE 0.0049
-#define INITIAL_RADIUS_COVARIANCE 400.0
-#define INITIAL_POSITION_COVARIANCE 400.0
+static constexpr float INITIAL_THERMAL_RADIUS = 80.0;
+static constexpr float INITIAL_STRENGTH_COVARIANCE = 0.0049;
+static constexpr float INITIAL_RADIUS_COVARIANCE = 400.0;
+static constexpr float INITIAL_POSITION_COVARIANCE = 400.0;
 
 
 class SoaringController {