diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_Measurements.cpp b/libraries/AP_NavEKF2/AP_NavEKF2_Measurements.cpp
index 0dd728669e..a7847b9b07 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_Measurements.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_Measurements.cpp
@@ -4,6 +4,7 @@
 #include <AP_Vehicle/AP_Vehicle.h>
 #include <GCS_MAVLink/GCS.h>
 #include <AP_DAL/AP_DAL.h>
+#include <AP_InternalError/AP_InternalError.h>
 
 extern const AP_HAL::HAL& hal;