diff --git a/Examples/Algorithms/TrackFitting/src/KalmanFitterFunction.cpp b/Examples/Algorithms/TrackFitting/src/KalmanFitterFunction.cpp
index 5b5417e73fc..43757f411ca 100644
--- a/Examples/Algorithms/TrackFitting/src/KalmanFitterFunction.cpp
+++ b/Examples/Algorithms/TrackFitting/src/KalmanFitterFunction.cpp
@@ -76,7 +76,7 @@ struct KalmanFitterFunctionImpl final : public TrackFitterFunction {
   Acts::GainMatrixUpdater kfUpdater;
   Acts::GainMatrixSmoother kfSmoother;
   SimpleReverseFilteringLogic reverseFilteringLogic;
-  double reverseFilteringCovarianceScaling;
+  double reverseFilteringCovarianceScaling = 1.0;
   bool multipleScattering = false;
   bool energyLoss = false;
   Acts::FreeToBoundCorrection freeToBoundCorrection;