diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.h b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
index 9179482f4d..adf8fb1a68 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.h
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
@@ -996,10 +996,11 @@ private:
     bool baroDataToFuse;            // true when valid baro height finder data has arrived at the fusion time horizon.
     bool gpsDataToFuse;             // true when valid GPS data has arrived at the fusion time horizon.
     bool magDataToFuse;             // true when valid magnetometer data has arrived at the fusion time horizon
-    enum AidingMode {AID_ABSOLUTE=0,    // GPS or some other form of absolute position reference aiding is being used (optical flow may also be used in parallel) so position estimates are absolute.
-                     AID_NONE=1,       // no aiding is being used so only attitude and height estimates are available. Either constVelMode or constPosMode must be used to constrain tilt drift.
-                     AID_RELATIVE=2    // only optical flow aiding is being used so position estimates will be relative
-                    };
+    enum AidingMode {
+        AID_ABSOLUTE=0,    // GPS or some other form of absolute position reference aiding is being used (optical flow may also be used in parallel) so position estimates are absolute.
+        AID_NONE=1,       // no aiding is being used so only attitude and height estimates are available. Either constVelMode or constPosMode must be used to constrain tilt drift.
+        AID_RELATIVE=2,    // only optical flow aiding is being used so position estimates will be relative
+    };
     AidingMode PV_AidingMode;       // Defines the preferred mode for aiding of velocity and position estimates from the INS
     AidingMode PV_AidingModePrev;   // Value of PV_AidingMode from the previous frame - used to detect transitions
     bool gndOffsetValid;            // true when the ground offset state can still be considered valid