diff --git a/EKF/estimator_interface.cpp b/EKF/estimator_interface.cpp
index 1592222b30..a648b9486a 100644
--- a/EKF/estimator_interface.cpp
+++ b/EKF/estimator_interface.cpp
@@ -47,8 +47,30 @@
 #include <mathlib/mathlib.h>
 
 
-EstimatorInterface::EstimatorInterface()
+EstimatorInterface::EstimatorInterface():
+	_dt_imu_avg(0.0f),
+	_imu_ticks(0),
+	_imu_updated(false),
+	_initialised(false),
+	_vehicle_armed(false),
+	_in_air(false),
+	_NED_origin_initialised(false),
+	_gps_speed_valid(false),
+	_gps_speed_accuracy(0.0f),
+	_mag_healthy(false),
+	_yaw_test_ratio(0.0f),
+	_time_last_imu(0),
+	_time_last_gps(0),
+	_time_last_mag(0),
+	_time_last_baro(0),
+	_time_last_range(0),
+	_time_last_airspeed(0),
+	_mag_declination_gps(0.0f),
+	_mag_declination_to_save_deg(0.0f)
 {
+    _pos_ref = {};
+    _mag_test_ratio = {};
+    _vel_pos_test_ratio = {};
 }
 
 EstimatorInterface::~EstimatorInterface()