diff --git a/tests/dynamics_model/test_lti_system.cpp b/tests/dynamics_model/test_lti_system.cpp
index b6011478..e459ae50 100644
--- a/tests/dynamics_model/test_lti_system.cpp
+++ b/tests/dynamics_model/test_lti_system.cpp
@@ -21,6 +21,7 @@
 #include "gtest/gtest.h"
 #include <unsupported/Eigen/MatrixFunctions>
 #include "dynamics_model/lti_system.hpp"
+#include <filesystem>
 
 namespace fs = std::filesystem;
 using namespace cddp;