diff --git a/src/tests/unit-tests/signal-processing-blocks/tracking/cubature_filter_test.cc b/src/tests/unit-tests/signal-processing-blocks/tracking/cubature_filter_test.cc
index 56e18df38..0833b12be 100644
--- a/src/tests/unit-tests/signal-processing-blocks/tracking/cubature_filter_test.cc
+++ b/src/tests/unit-tests/signal-processing-blocks/tracking/cubature_filter_test.cc
@@ -39,7 +39,7 @@
 class TransitionModel : public ModelFunction
 {
 public:
-    TransitionModel(const arma::mat& kf_F) { coeff_mat = kf_F; };
+    explicit TransitionModel(const arma::mat& kf_F) { coeff_mat = kf_F; };
     virtual arma::vec operator()(const arma::vec& input) { return coeff_mat * input; };
 
 private:
@@ -49,7 +49,7 @@ private:
 class MeasurementModel : public ModelFunction
 {
 public:
-    MeasurementModel(const arma::mat& kf_H) { coeff_mat = kf_H; };
+    explicit MeasurementModel(const arma::mat& kf_H) { coeff_mat = kf_H; };
     virtual arma::vec operator()(const arma::vec& input) { return coeff_mat * input; };
 
 private:
diff --git a/src/tests/unit-tests/signal-processing-blocks/tracking/unscented_filter_test.cc b/src/tests/unit-tests/signal-processing-blocks/tracking/unscented_filter_test.cc
index eaef07845..bc9e5315d 100644
--- a/src/tests/unit-tests/signal-processing-blocks/tracking/unscented_filter_test.cc
+++ b/src/tests/unit-tests/signal-processing-blocks/tracking/unscented_filter_test.cc
@@ -39,7 +39,7 @@
 class TransitionModelUKF : public ModelFunction
 {
 public:
-    TransitionModelUKF(const arma::mat& kf_F) { coeff_mat = kf_F; };
+    explicit TransitionModelUKF(const arma::mat& kf_F) { coeff_mat = kf_F; };
     virtual arma::vec operator()(const arma::vec& input) { return coeff_mat * input; };
 
 private:
@@ -49,7 +49,7 @@ private:
 class MeasurementModelUKF : public ModelFunction
 {
 public:
-    MeasurementModelUKF(const arma::mat& kf_H) { coeff_mat = kf_H; };
+    explicit MeasurementModelUKF(const arma::mat& kf_H) { coeff_mat = kf_H; };
     virtual arma::vec operator()(const arma::vec& input) { return coeff_mat * input; };
 
 private: