diff --git a/EKF/drag_fusion.cpp b/EKF/drag_fusion.cpp
index a0cc3a31ab..1f95728fcb 100644
--- a/EKF/drag_fusion.cpp
+++ b/EKF/drag_fusion.cpp
@@ -48,8 +48,8 @@ void Ekf::fuseDrag()
 {
 	SparseVector24f<0,1,2,3,4,5,6,22,23> Hfusion;  // Observation Jacobians
 	Vector24f Kfusion; // Kalman gain vector
-	const float R_ACC = sq(_params.drag_noise); // observation noise variance in specific force drag (m/sec**2)**2
 
+	const float R_ACC = fmaxf(_params.drag_noise, 0.5f); // observation noise variance in specific force drag (m/sec**2)**2
 	const float rho = fmaxf(_air_density, 0.1f); // air density (kg/m**3)
 
 	// calculate inverse of ballistic coefficient