diff --git a/example/test/example_test_gtest.cpp b/example/test/example_test_gtest.cpp
index 40e06e1..8d1155d 100644
--- a/example/test/example_test_gtest.cpp
+++ b/example/test/example_test_gtest.cpp
@@ -65,7 +65,7 @@ TEST_F(ExampleTest, check_parameters) {
 }
 
 TEST_F(ExampleTest, try_get_params) {
-  ASSERT_TRUE(param_listener_->try_get_params(params_));
+  ASSERT_FALSE(param_listener_->try_get_params(params_));
 
   const rclcpp ::Parameter new_param("interpolation_mode", "linear");
   example_test_node_->set_parameter(new_param);
diff --git a/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/cpp/parameter_library_header b/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/cpp/parameter_library_header
index 179d506..909b9bf 100644
--- a/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/cpp/parameter_library_header
+++ b/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/cpp/parameter_library_header
@@ -125,12 +125,12 @@ struct StackParams {
     }
 
     bool try_get_params(Params & params_in) const {
-      if (mutex_.try_lock()) {
+      std::unique_lock<std::mutex> lock(mutex_, std::try_to_lock);
+      if (lock.owns_lock()) {
         if (const bool is_old = params_in.__stamp != params_.__stamp; is_old) {
           params_in = params_;
+          return true;
         }
-        mutex_.unlock();
-        return true;
       }
       return false;
     }