diff --git a/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_control.cpp b/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_control.cpp
index 390a957992..3c4c031f31 100644
--- a/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_control.cpp
+++ b/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_control.cpp
@@ -89,8 +89,9 @@ void Ekf::controlOpticalFlowFusion(const imuSample &imu_delayed)
 		// calculate the optical flow observation variance
 		const float R_LOS = calcOptFlowMeasVar(flow_sample);
 
+		const float epsilon = 1e-3f;
 		Vector2f innov_var;
-		sym::ComputeFlowXyInnovVarAndHx(_state.vector(), P, R_LOS, FLT_EPSILON, &innov_var, &H);
+		sym::ComputeFlowXyInnovVarAndHx(_state.vector(), P, R_LOS, epsilon, &innov_var, &H);
 
 		// run the innovation consistency check and record result
 		updateAidSourceStatus(_aid_src_optical_flow,
diff --git a/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_fusion.cpp b/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_fusion.cpp
index 531a7b56d0..860c6eca5e 100644
--- a/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_fusion.cpp
+++ b/src/modules/ekf2/EKF/aid_sources/optical_flow/optical_flow_fusion.cpp
@@ -72,7 +72,8 @@ bool Ekf::fuseOptFlow(VectorState &H, const bool update_terrain)
 		} else if (index == 1) {
 			// recalculate innovation variance because state covariances have changed due to previous fusion (linearise using the same initial state for all axes)
 			const float R_LOS = _aid_src_optical_flow.observation_variance[1];
-			sym::ComputeFlowYInnovVarAndH(state_vector, P, R_LOS, FLT_EPSILON, &_aid_src_optical_flow.innovation_variance[1], &H);
+			const float epsilon = 1e-3f;
+			sym::ComputeFlowYInnovVarAndH(state_vector, P, R_LOS, epsilon, &_aid_src_optical_flow.innovation_variance[1], &H);
 
 			// recalculate the innovation using the updated state
 			const Vector3f flow_gyro_corrected = _flow_sample_delayed.gyro_rate - _flow_gyro_bias;