diff --git a/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.cpp b/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.cpp
index 892ad17842..db0ae29511 100644
--- a/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.cpp
+++ b/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.cpp
@@ -21,7 +21,7 @@ void CustomAPIDeviceComponent::setup() {
 
 void CustomAPIDeviceComponent::on_test_service() { ESP_LOGI(TAG, "Custom test service called!"); }
 
-void CustomAPIDeviceComponent::on_service_with_args(std::string arg_string, int32_t arg_int, bool arg_bool,
+void CustomAPIDeviceComponent::on_service_with_args(const std::string &arg_string, int32_t arg_int, bool arg_bool,
                                                     float arg_float) {
   ESP_LOGI(TAG, "Custom service called with: %s, %d, %d, %.2f", arg_string.c_str(), arg_int, arg_bool, arg_float);
 }
diff --git a/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.h b/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.h
index cdfda63348..21071c4430 100644
--- a/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.h
+++ b/tests/integration/fixtures/external_components/custom_api_device_component/custom_api_device_component.h
@@ -17,7 +17,7 @@ class CustomAPIDeviceComponent : public Component, public CustomAPIDevice {
 
   void on_test_service();
 
-  void on_service_with_args(std::string arg_string, int32_t arg_int, bool arg_bool, float arg_float);
+  void on_service_with_args(const std::string &arg_string, int32_t arg_int, bool arg_bool, float arg_float);
 
   void on_service_with_arrays(std::vector<bool> bool_array, std::vector<int32_t> int_array,
                               std::vector<float> float_array, std::vector<std::string> string_array);