diff --git a/src/modules/commander/failure_detector/FailureDetector.cpp b/src/modules/commander/failure_detector/FailureDetector.cpp
index c0e7d55937..007528211b 100644
--- a/src/modules/commander/failure_detector/FailureDetector.cpp
+++ b/src/modules/commander/failure_detector/FailureDetector.cpp
@@ -329,9 +329,9 @@ void FailureDetector::updateImbalancedPropStatus()
 
 				_imbalanced_prop_lpf.setParameters(dt, _imbalanced_prop_lpf_time_constant);
 
-				const float std_x = sqrtf(imu_status.var_accel[0]);
-				const float std_y = sqrtf(imu_status.var_accel[1]);
-				const float std_z = sqrtf(imu_status.var_accel[2]);
+				const float std_x = sqrtf(math::max(imu_status.var_accel[0], 0.f));
+				const float std_y = sqrtf(math::max(imu_status.var_accel[1], 0.f));
+				const float std_z = sqrtf(math::max(imu_status.var_accel[2], 0.f));
 
 				// Note: the metric is done using standard deviations instead of variances to be linear
 				const float metric = (std_x + std_y) / 2.f - std_z;