diff --git a/src/modules/ekf2/EKF/bias_estimator.hpp b/src/modules/ekf2/EKF/bias_estimator.hpp
index 53f82dc03c..d810fc1d07 100644
--- a/src/modules/ekf2/EKF/bias_estimator.hpp
+++ b/src/modules/ekf2/EKF/bias_estimator.hpp
@@ -47,7 +47,8 @@
  * @author Mathieu Bresciani 	<mathieu@auterion.com>
  */
 
-#pragma once
+#ifndef EKF_BIAS_ESTIMATOR_HPP
+#define EKF_BIAS_ESTIMATOR_HPP
 
 #include <matrix/math.hpp>
 #include <mathlib/mathlib.h>
@@ -133,3 +134,5 @@ private:
 	static constexpr float _innov_sequence_monitnoring_time_constant{10.f}; ///< in seconds
 	static constexpr float _process_var_boost_gain{1.0e3f};
 };
+
+#endif // !EKF_BIAS_ESTIMATOR_HPP
diff --git a/src/modules/ekf2/EKF/height_bias_estimator.hpp b/src/modules/ekf2/EKF/height_bias_estimator.hpp
index 9082842b9e..1d1b9629f5 100644
--- a/src/modules/ekf2/EKF/height_bias_estimator.hpp
+++ b/src/modules/ekf2/EKF/height_bias_estimator.hpp
@@ -35,7 +35,8 @@
  * @file height_bias_estimator.hpp
  */
 
-#pragma once
+#ifndef EKF_HEIGHT_BIAS_ESTIMATOR_HPP
+#define EKF_HEIGHT_BIAS_ESTIMATOR_HPP
 
 #include "bias_estimator.hpp"
 
@@ -72,3 +73,5 @@ private:
 
 	bool _is_sensor_fusion_active{false}; // TODO: replace by const ref and remove setter when migrating _control_status.flags from union to bool
 };
+
+#endif // !EKF_HEIGHT_BIAS_ESTIMATOR_HPP
diff --git a/src/modules/ekf2/EKF/position_bias_estimator.hpp b/src/modules/ekf2/EKF/position_bias_estimator.hpp
index ddcbe144ce..0e997e2d28 100644
--- a/src/modules/ekf2/EKF/position_bias_estimator.hpp
+++ b/src/modules/ekf2/EKF/position_bias_estimator.hpp
@@ -35,7 +35,8 @@
  * @file position_bias_estimator.hpp
  */
 
-#pragma once
+#ifndef EKF_POSITION_BIAS_ESTIMATOR_HPP
+#define EKF_POSITION_BIAS_ESTIMATOR_HPP
 
 #include "bias_estimator.hpp"
 
@@ -111,3 +112,5 @@ private:
 
 	bool _is_sensor_fusion_active{false}; // TODO: replace by const ref and remove setter when migrating _control_status.flags from union to bool
 };
+
+#endif // !EKF_POSITION_BIAS_ESTIMATOR_HPP
diff --git a/src/modules/ekf2/EKF/range_finder_consistency_check.hpp b/src/modules/ekf2/EKF/range_finder_consistency_check.hpp
index 1498a4aa6c..4237c3f437 100644
--- a/src/modules/ekf2/EKF/range_finder_consistency_check.hpp
+++ b/src/modules/ekf2/EKF/range_finder_consistency_check.hpp
@@ -37,7 +37,8 @@
  * using the estimated velocity as a reference in order to detect sensor faults
  */
 
-#pragma once
+#ifndef EKF_RANGE_FINDER_CONSISTENCY_CHECK_HPP
+#define EKF_RANGE_FINDER_CONSISTENCY_CHECK_HPP
 
 #include <mathlib/math/filter/AlphaFilter.hpp>
 
@@ -77,3 +78,5 @@ private:
 	static constexpr float _min_vz_for_valid_consistency = .5f;
 	static constexpr uint64_t _consistency_hyst_time_us = 1e6;
 };
+
+#endif // !EKF_RANGE_FINDER_CONSISTENCY_CHECK_HPP