diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
index 94765ea2dd..9be77903f7 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
@@ -238,6 +238,7 @@ void NavEKF2_core::InitialiseVariables()
     runUpdates = false;
     framesSincePredict = 0;
     gpsYawResetRequest = false;
+    stateStruct.quat.initialise();
     quatAtLastMagReset = stateStruct.quat;
     delAngBiasLearned = false;
     memset(&filterStatus, 0, sizeof(filterStatus));