diff --git a/core/include/traccc/fitting/kalman_filter/gain_matrix_updater.hpp b/core/include/traccc/fitting/kalman_filter/gain_matrix_updater.hpp
index f1e68c493..824aaee27 100644
--- a/core/include/traccc/fitting/kalman_filter/gain_matrix_updater.hpp
+++ b/core/include/traccc/fitting/kalman_filter/gain_matrix_updater.hpp
@@ -121,6 +121,12 @@ struct gain_matrix_updater {
         const matrix_type<1, 1> chi2 = matrix_operator().transpose(residual) *
                                        matrix_operator().inverse(R) * residual;
 
+        // Make sure that the sign of qop does not change (This rarely happens
+        // when qop is set with a poor seed resolution)
+        assert(bound_params[e_bound_qoverp] *
+                   getter::element(filtered_vec, e_bound_qoverp, 0u) >
+               0.f);
+
         // Set the stepper parameter
         bound_params.set_vector(filtered_vec);
         bound_params.set_covariance(filtered_cov);
diff --git a/examples/run/cpu/truth_fitting_example.cpp b/examples/run/cpu/truth_fitting_example.cpp
index 20c707c37..ab0e9cd69 100644
--- a/examples/run/cpu/truth_fitting_example.cpp
+++ b/examples/run/cpu/truth_fitting_example.cpp
@@ -111,7 +111,7 @@ int main(int argc, char* argv[]) {
         0.03f * detray::unit<scalar>::mm,
         0.017f,
         0.017f,
-        0.01f / detray::unit<scalar>::GeV,
+        0.001f / detray::unit<scalar>::GeV,
         1.f * detray::unit<scalar>::ns};
 
     // Fitting algorithm object
diff --git a/examples/run/cuda/truth_fitting_example_cuda.cpp b/examples/run/cuda/truth_fitting_example_cuda.cpp
index 7d5f485e7..672a66306 100644
--- a/examples/run/cuda/truth_fitting_example_cuda.cpp
+++ b/examples/run/cuda/truth_fitting_example_cuda.cpp
@@ -153,7 +153,7 @@ int main(int argc, char* argv[]) {
         0.03f * detray::unit<scalar>::mm,
         0.017f,
         0.017f,
-        0.01f / detray::unit<scalar>::GeV,
+        0.001f / detray::unit<scalar>::GeV,
         1.f * detray::unit<scalar>::ns};
 
     // Fitting algorithm object
diff --git a/tests/common/tests/kalman_fitting_toy_detector_test.hpp b/tests/common/tests/kalman_fitting_toy_detector_test.hpp
index 2bcfb91a8..365dfc982 100644
--- a/tests/common/tests/kalman_fitting_toy_detector_test.hpp
+++ b/tests/common/tests/kalman_fitting_toy_detector_test.hpp
@@ -49,7 +49,7 @@ class KalmanFittingToyDetectorTests : public KalmanFittingTests {
         0.01f * detray::unit<scalar>::mm,
         0.001f,
         0.001f,
-        0.01f / detray::unit<scalar>::GeV,
+        0.001f / detray::unit<scalar>::GeV,
         0.01f * detray::unit<scalar>::ns};
 
     protected: