diff --git a/firmware/application/file.cpp b/firmware/application/file.cpp
index 439c0a9c..4898ee74 100644
--- a/firmware/application/file.cpp
+++ b/firmware/application/file.cpp
@@ -25,7 +25,7 @@ File::~File() {
 	close();
 }
 
-bool File::open_for_append(const std::string file_path) {
+bool File::open_for_append(const std::string& file_path) {
 	const auto open_result = f_open(&f, file_path.c_str(), FA_WRITE | FA_OPEN_ALWAYS);
 	if( open_result == FR_OK ) {
 		const auto seek_result = f_lseek(&f, f_size(&f));
@@ -60,7 +60,7 @@ bool File::write(const void* const data, const size_t bytes_to_write) {
 	return (result == FR_OK) && (bytes_written == bytes_to_write);
 }
 
-bool File::puts(const std::string string) {
+bool File::puts(const std::string& string) {
 	const auto result = f_puts(string.c_str(), &f);
 	return (result >= 0);
 }
diff --git a/firmware/application/file.hpp b/firmware/application/file.hpp
index 363bd866..24705a8e 100644
--- a/firmware/application/file.hpp
+++ b/firmware/application/file.hpp
@@ -31,7 +31,7 @@ class File {
 public:
 	~File();
 
-	bool open_for_append(const std::string file_path);
+	bool open_for_append(const std::string& file_path);
 	bool close();
 
 	bool is_ready();
@@ -39,7 +39,7 @@ public:
 	bool read(void* const data, const size_t bytes_to_read);
 	bool write(const void* const data, const size_t bytes_to_write);
 
-	bool puts(const std::string string);
+	bool puts(const std::string& string);
 
 	bool sync();
 
diff --git a/firmware/application/ui_console.cpp b/firmware/application/ui_console.cpp
index 65482236..28b9f298 100644
--- a/firmware/application/ui_console.cpp
+++ b/firmware/application/ui_console.cpp
@@ -35,7 +35,7 @@ void Console::clear() {
 	display.scroll_set_position(0);
 }
 
-void Console::write(const std::string message) {
+void Console::write(const std::string& message) {
 	const Style& s = style();
 	const Font& font = s.font;
 	const auto rect = screen_rect();
@@ -58,7 +58,7 @@ void Console::write(const std::string message) {
 	}
 }
 
-void Console::writeln(const std::string message) {
+void Console::writeln(const std::string& message) {
 	write(message);
 	crlf();
 }
diff --git a/firmware/application/ui_console.hpp b/firmware/application/ui_console.hpp
index 4f29486a..db49acc7 100644
--- a/firmware/application/ui_console.hpp
+++ b/firmware/application/ui_console.hpp
@@ -33,8 +33,8 @@ namespace ui {
 class Console : public Widget {
 public:
 	void clear();
-	void write(const std::string message);
-	void writeln(const std::string message);
+	void write(const std::string& message);
+	void writeln(const std::string& message);
 
 	void paint(Painter& painter) override;
 	
diff --git a/firmware/application/ui_menu.hpp b/firmware/application/ui_menu.hpp
index 5863e048..3c01e98c 100644
--- a/firmware/application/ui_menu.hpp
+++ b/firmware/application/ui_menu.hpp
@@ -70,7 +70,7 @@ public:
 	void add_item(const MenuItem item);
 
 	template<size_t N>
-	void add_items(const std::array<MenuItem, N> items) {
+	void add_items(const std::array<MenuItem, N>& items) {
 		for(const auto& item : items) {
 			add_item(item);
 		}
diff --git a/firmware/application/ui_setup.cpp b/firmware/application/ui_setup.cpp
index 596d1534..95beba9b 100644
--- a/firmware/application/ui_setup.cpp
+++ b/firmware/application/ui_setup.cpp
@@ -82,7 +82,7 @@ void SetDateTimeView::focus() {
 	button_cancel.focus();
 }
 
-void SetDateTimeView::form_init(const SetDateTimeModel model) {
+void SetDateTimeView::form_init(const SetDateTimeModel& model) {
 	field_year.set_value(model.year);
 	field_month.set_value(model.month);
 	field_day.set_value(model.day);
@@ -134,7 +134,7 @@ void SetFrequencyCorrectionView::focus() {
 	button_cancel.focus();
 }
 
-void SetFrequencyCorrectionView::form_init(const SetFrequencyCorrectionModel model) {
+void SetFrequencyCorrectionView::form_init(const SetFrequencyCorrectionModel& model) {
 	field_ppm.set_value(model.ppm);
 }
 
diff --git a/firmware/application/ui_setup.hpp b/firmware/application/ui_setup.hpp
index c012d5fc..cb205292 100644
--- a/firmware/application/ui_setup.hpp
+++ b/firmware/application/ui_setup.hpp
@@ -128,7 +128,7 @@ private:
 		"Cancel",
 	};
 
-	void form_init(const SetDateTimeModel model);
+	void form_init(const SetDateTimeModel& model);
 	SetDateTimeModel form_collect();
 };
 
@@ -172,7 +172,7 @@ private:
 		"Cancel",
 	};
 
-	void form_init(const SetFrequencyCorrectionModel model);
+	void form_init(const SetFrequencyCorrectionModel& model);
 	SetFrequencyCorrectionModel form_collect();
 };