diff --git a/test/gtest_simulation_problem_force_torque_inertial_dynamics.cpp b/test/gtest_simulation_problem_force_torque_inertial_dynamics.cpp
index 202bf117ba164cc4e3bb29c61b842329ce723c3c..64ab43627674118f196b43bccc4b05c15fed4ba8 100644
--- a/test/gtest_simulation_problem_force_torque_inertial_dynamics.cpp
+++ b/test/gtest_simulation_problem_force_torque_inertial_dynamics.cpp
@@ -80,9 +80,6 @@ class Test_SimulationProblemForceTorqueInertialDynamics_yaml : public testing::T
     std::vector<Vector3d>                   position, vlin, vang, force, torque, a_meas;
     std::vector<Quaterniond>                quaternion;
 
-    // Fitxer CSV
-    std::fstream fout;
-
   protected:
     void extractAndCompleteData(const std::string& file_path_name)
     {
@@ -250,6 +247,7 @@ TEST_F(Test_SimulationProblemForceTorqueInertialDynamics_yaml, preintegration_an
 {
     std::string wolf_bodydynamics_root = _WOLF_BODYDYNAMICS_ROOT_DIR;
     // creem un nou arxiu CSV per imprimir els estats que estem rebent ara
+    std::fstream fout;
     fout.open(wolf_bodydynamics_root + "/test/dades_simulacio_pep_estimador.csv",
                 std::fstream::out | std::fstream::trunc);