diff --git a/EKF/covariance.cpp b/EKF/covariance.cpp
index 94bafced3e..1408019240 100644
--- a/EKF/covariance.cpp
+++ b/EKF/covariance.cpp
@@ -1084,6 +1084,13 @@ void Ekf::zeroMagCov()
 	P.uncorrelateCovarianceSetVariance<3>(19, 0.0f);
 }
 
+void Ekf::resetZDeltaAngBiasCov()
+{
+	const float init_delta_ang_bias_var = sq(_params.switch_on_gyro_bias * _dt_ekf_avg);
+
+	P.uncorrelateCovarianceSetVariance<1>(12, init_delta_ang_bias_var);
+}
+
 void Ekf::resetWindCovariance()
 {
 	if (_tas_data_ready && (_imu_sample_delayed.time_us - _airspeed_sample_delayed.time_us < (uint64_t)5e5)) {
diff --git a/EKF/ekf.h b/EKF/ekf.h
index af858cf585..58054d69a5 100644
--- a/EKF/ekf.h
+++ b/EKF/ekf.h
@@ -926,6 +926,8 @@ private:
 	void clearMagCov();
 	void zeroMagCov();
 
+	void resetZDeltaAngBiasCov();
+
 	// uncorrelate quaternion states from other states
 	void uncorrelateQuatFromOtherStates();
 
diff --git a/EKF/mag_fusion.cpp b/EKF/mag_fusion.cpp
index 9d3a55aa2e..5a799f8119 100644
--- a/EKF/mag_fusion.cpp
+++ b/EKF/mag_fusion.cpp
@@ -653,6 +653,10 @@ void Ekf::updateQuaternion(const float innovation, const float variance, const f
 			float gate_limit = sqrtf((sq(gate_sigma) * _heading_innov_var));
 			_heading_innov = math::constrain(innovation, -gate_limit, gate_limit);
 
+			// also reset the yaw gyro variance to converge faster and avoid
+			// being stuck on a previous bad estimate
+			resetZDeltaAngBiasCov();
+
 		} else {
 			return;
 		}