diff --git a/core/include/traccc/edm/track_state.hpp b/core/include/traccc/edm/track_state.hpp
index 1e016fee9..ded4e311e 100644
--- a/core/include/traccc/edm/track_state.hpp
+++ b/core/include/traccc/edm/track_state.hpp
@@ -32,6 +32,10 @@ struct fitting_result {
 
     /// Chi square of fitted track
     scalar_type chi2{0};
+
+    // The number of holes (The number of sensitive surfaces which do not have a
+    // measurement for the track pattern)
+    unsigned int n_holes{0u};
 };
 
 /// Fitting result per measurement
diff --git a/core/include/traccc/fitting/kalman_filter/kalman_actor.hpp b/core/include/traccc/fitting/kalman_filter/kalman_actor.hpp
index 9db5b1fd3..56522bfb5 100644
--- a/core/include/traccc/fitting/kalman_filter/kalman_actor.hpp
+++ b/core/include/traccc/fitting/kalman_filter/kalman_actor.hpp
@@ -68,6 +68,10 @@ struct kalman_actor : detray::actor {
 
         // iterator for forward filtering
         typename vector_t<track_state_type>::iterator m_it;
+
+        // The number of holes (The number of sensitive surfaces which do not
+        // have a measurement for the track pattern)
+        unsigned int n_holes{0u};
     };
 
     /// Actor operation to perform the Kalman filtering
@@ -92,9 +96,10 @@ struct kalman_actor : detray::actor {
 
             auto& trk_state = actor_state();
 
-            // Abort if the propagator fails to find the next measurement
+            // Increase the hole counts if the propagator fails to find the next
+            // measurement
             if (navigation.barcode() != trk_state.surface_link()) {
-                // propagation._heartbeat &= navigation.abort();
+                actor_state.n_holes++;
                 return;
             }
 
diff --git a/core/include/traccc/fitting/kalman_filter/kalman_fitter.hpp b/core/include/traccc/fitting/kalman_filter/kalman_fitter.hpp
index 31b07dcba..18a189ec9 100644
--- a/core/include/traccc/fitting/kalman_filter/kalman_fitter.hpp
+++ b/core/include/traccc/fitting/kalman_filter/kalman_fitter.hpp
@@ -239,6 +239,9 @@ class kalman_fitter {
 
         // Subtract the NDoF with the degree of freedom of the bound track (=5)
         fit_res.ndf = fit_res.ndf - 5.f;
+
+        // The number of holes
+        fit_res.n_holes = fitter_state.m_fit_actor_state.n_holes;
     }
 
     private:
diff --git a/tests/cpu/CMakeLists.txt b/tests/cpu/CMakeLists.txt
index bd793bfca..c6c03be08 100644
--- a/tests/cpu/CMakeLists.txt
+++ b/tests/cpu/CMakeLists.txt
@@ -13,6 +13,7 @@ traccc_add_test(cpu
     "test_ckf_sparse_tracks_telescope.cpp"
     "test_clusterization_resolution.cpp"
     "test_copy.cpp"
+    "test_kalman_fitter_hole_count.cpp"
     "test_kalman_fitter_telescope.cpp"
     "test_kalman_fitter_wire_chamber.cpp"
     "test_ranges.cpp"
diff --git a/tests/cpu/test_kalman_fitter_hole_count.cpp b/tests/cpu/test_kalman_fitter_hole_count.cpp
new file mode 100644
index 000000000..f1e35b25e
--- /dev/null
+++ b/tests/cpu/test_kalman_fitter_hole_count.cpp
@@ -0,0 +1,184 @@
+/** TRACCC library, part of the ACTS project (R&D line)
+ *
+ * (c) 2024 CERN for the benefit of the ACTS project
+ *
+ * Mozilla Public License Version 2.0
+ */
+
+// Project include(s).
+#include "traccc/edm/track_state.hpp"
+#include "traccc/fitting/kalman_fitting_algorithm.hpp"
+#include "traccc/io/utils.hpp"
+#include "traccc/resolution/fitting_performance_writer.hpp"
+#include "traccc/simulation/simulator.hpp"
+#include "traccc/utils/ranges.hpp"
+#include "traccc/utils/seed_generator.hpp"
+
+// Test include(s).
+#include "tests/kalman_fitting_telescope_test.hpp"
+
+// detray include(s).
+#include "detray/io/frontend/detector_reader.hpp"
+#include "detray/test/utils/simulation/event_generator/track_generators.hpp"
+
+// VecMem include(s).
+#include <vecmem/memory/host_memory_resource.hpp>
+
+// GTest include(s).
+#include <gtest/gtest.h>
+
+// System include(s).
+#include <filesystem>
+#include <string>
+
+using namespace traccc;
+
+class KalmanFittingHoleCountTests : public KalmanFittingTelescopeTests {};
+
+TEST_P(KalmanFittingHoleCountTests, Run) {
+
+    // Get the parameters
+    const std::string name = std::get<0>(GetParam());
+    const std::array<scalar, 3u> origin = std::get<1>(GetParam());
+    const std::array<scalar, 3u> origin_stddev = std::get<2>(GetParam());
+    const std::array<scalar, 2u> mom_range = std::get<3>(GetParam());
+    const std::array<scalar, 2u> eta_range = std::get<4>(GetParam());
+    const std::array<scalar, 2u> theta_range = eta_to_theta_range(eta_range);
+    const std::array<scalar, 2u> phi_range = std::get<5>(GetParam());
+    const detray::pdg_particle<scalar> ptc = std::get<6>(GetParam());
+    const unsigned int n_truth_tracks = std::get<7>(GetParam());
+    const unsigned int n_events = std::get<8>(GetParam());
+    const bool random_charge = std::get<9>(GetParam());
+
+    // We only test one track of one event
+    ASSERT_EQ(n_truth_tracks, 1u);
+    ASSERT_EQ(n_events, 1u);
+
+    /*****************************
+     * Build a telescope geometry
+     *****************************/
+
+    // Memory resources used by the application.
+    vecmem::host_memory_resource host_mr;
+
+    // Read back detector file
+    const std::string path = name + "/";
+    detray::io::detector_reader_config reader_cfg{};
+    reader_cfg.add_file(path + "telescope_detector_geometry.json")
+        .add_file(path + "telescope_detector_homogeneous_material.json");
+
+    const auto [host_det, names] =
+        detray::io::read_detector<host_detector_type>(host_mr, reader_cfg);
+    auto field = detray::bfield::create_const_field(B);
+
+    /***************************
+     * Generate simulation data
+     ***************************/
+
+    // Track generator
+    using generator_type =
+        detray::random_track_generator<traccc::free_track_parameters,
+                                       uniform_gen_t>;
+    generator_type::configuration gen_cfg{};
+    gen_cfg.n_tracks(n_truth_tracks);
+    gen_cfg.origin(origin);
+    gen_cfg.origin_stddev(origin_stddev);
+    gen_cfg.phi_range(phi_range[0], phi_range[1]);
+    gen_cfg.theta_range(theta_range[0], theta_range[1]);
+    gen_cfg.mom_range(mom_range[0], mom_range[1]);
+    gen_cfg.randomize_charge(random_charge);
+    generator_type generator(gen_cfg);
+
+    // Smearing value for measurements
+    traccc::measurement_smearer<traccc::default_algebra> meas_smearer(
+        smearing[0], smearing[1]);
+
+    using writer_type = traccc::smearing_writer<
+        traccc::measurement_smearer<traccc::default_algebra>>;
+
+    typename writer_type::config smearer_writer_cfg{meas_smearer};
+
+    // Run simulator
+    const std::string full_path = io::data_directory() + path;
+    std::filesystem::create_directories(full_path);
+    auto sim = traccc::simulator<host_detector_type, b_field_t, generator_type,
+                                 writer_type>(
+        ptc, n_events, host_det, field, std::move(generator),
+        std::move(smearer_writer_cfg), full_path);
+    sim.get_config().propagation.navigation.overstep_tolerance =
+        -100.f * unit<float>::um;
+    sim.get_config().propagation.navigation.max_mask_tolerance =
+        1.f * unit<float>::mm;
+    sim.run();
+
+    /***************
+     * Run fitting
+     ***************/
+
+    // Seed generator
+    seed_generator<host_detector_type> sg(host_det, stddevs);
+
+    // Fitting algorithm object
+    traccc::fitting_config fit_cfg;
+    fit_cfg.ptc_hypothesis = ptc;
+    fit_cfg.propagation.navigation.overstep_tolerance =
+        -100.f * unit<float>::um;
+    fit_cfg.propagation.navigation.max_mask_tolerance = 1.f * unit<float>::mm;
+    traccc::host::kalman_fitting_algorithm fitting(fit_cfg, host_mr);
+
+    // Event map
+    traccc::event_data evt_data(path, 0u, host_mr);
+
+    // Truth Track Candidates
+    traccc::track_candidate_container_types::host track_candidates =
+        evt_data.generate_truth_candidates(sg, host_mr);
+    // Candidate vector
+    auto& cands = track_candidates.at(0u).items;
+
+    // Some sanity checks
+    ASSERT_EQ(track_candidates.size(), n_truth_tracks);
+    const auto n_planes = std::get<11>(GetParam());
+    ASSERT_EQ(cands.size(), n_planes);
+
+    // Pop some track candidates to create holes
+    // => The number of holes = 8
+    ASSERT_TRUE(cands.size() > 8u);
+    cands.erase(cands.begin());
+    cands.erase(cands.begin());
+    cands.erase(cands.begin() + 2);
+    cands.erase(cands.begin() + 2);
+    cands.erase(cands.begin() + 7);
+    cands.pop_back();
+    cands.pop_back();
+    cands.pop_back();
+
+    // A sanity check on the number of candidiates
+    ASSERT_EQ(cands.size(), n_planes - 8u);
+
+    // Run fitting
+    auto track_states =
+        fitting(host_det, field, traccc::get_data(track_candidates));
+
+    // A sanity check
+    const std::size_t n_tracks = track_states.size();
+    ASSERT_EQ(n_tracks, n_truth_tracks);
+
+    // Check the number of holes
+    // The three holes at the end are not counted as KF aborts once it goes
+    // through all track candidates
+    const auto& fit_res = track_states.at(0u).header;
+    ASSERT_EQ(fit_res.n_holes, 5u);
+
+    // Some sanity checks
+    ASSERT_FLOAT_EQ(
+        static_cast<float>(fit_res.ndf),
+        static_cast<float>(track_states.at(0u).items.size()) * 2.f - 5.f);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    KalmanFittingHoleCount, KalmanFittingHoleCountTests,
+    ::testing::Values(std::make_tuple(
+        "telescope_1_GeV_0_phi_muon", std::array<scalar, 3u>{0.f, 0.f, 0.f},
+        std::array<scalar, 3u>{0.f, 0.f, 0.f}, std::array<scalar, 2u>{1.f, 1.f},
+        std::array<scalar, 2u>{0.f, 0.f}, std::array<scalar, 2u>{0.f, 0.f},
+        detray::muon<scalar>(), 1, 1, false, 20.f, 20u, 20.f)));
diff --git a/tests/cpu/test_kalman_fitter_telescope.cpp b/tests/cpu/test_kalman_fitter_telescope.cpp
index f58fd80dc..f05ce0803 100644
--- a/tests/cpu/test_kalman_fitter_telescope.cpp
+++ b/tests/cpu/test_kalman_fitter_telescope.cpp
@@ -156,6 +156,8 @@ TEST_P(KalmanFittingTelescopeTests, Run) {
 
             ndf_tests(fit_res, track_states_per_track);
 
+            ASSERT_EQ(fit_res.n_holes, 0u);
+
             fit_performance_writer.write(track_states_per_track, fit_res,
                                          host_det, evt_data);
         }