diff --git a/ui/image/image_prepare.cpp b/ui/image/image_prepare.cpp
index 5833500..98e3065 100644
--- a/ui/image/image_prepare.cpp
+++ b/ui/image/image_prepare.cpp
@@ -866,7 +866,7 @@ QImage GenerateLinearGradient(
 		auto stops = QGradientStops();
 		const auto step = 1. / (colors.size() - 1);
 		auto point = 0.;
-		for (const auto color : colors) {
+		for (const auto &color : colors) {
 			stops.append({ point, color });
 			point += step;
 		}
diff --git a/ui/layers/box_content.cpp b/ui/layers/box_content.cpp
index d27c19e..66b2d08 100644
--- a/ui/layers/box_content.cpp
+++ b/ui/layers/box_content.cpp
@@ -245,7 +245,7 @@ void BoxContent::paintEvent(QPaintEvent *e) {
 
 	if (testAttribute(Qt::WA_OpaquePaintEvent)) {
 		const auto &color = getDelegate()->style().bg;
-		for (const auto rect : e->region()) {
+		for (const auto &rect : e->region()) {
 			p.fillRect(rect, color);
 		}
 	}
diff --git a/ui/layers/box_layer_widget.cpp b/ui/layers/box_layer_widget.cpp
index a7075ec..02a7d75 100644
--- a/ui/layers/box_layer_widget.cpp
+++ b/ui/layers/box_layer_widget.cpp
@@ -126,7 +126,7 @@ void BoxLayerWidget::paintEvent(QPaintEvent *e) {
 	}
 	auto other = e->region().intersected(QRect(0, st::boxRadius, width(), height() - 2 * st::boxRadius));
 	if (!other.isEmpty()) {
-		for (const auto rect : other) {
+		for (const auto &rect : other) {
 			p.fillRect(rect, st().bg);
 		}
 	}
diff --git a/ui/layers/layer_widget.cpp b/ui/layers/layer_widget.cpp
index 8e70249..7d8722c 100644
--- a/ui/layers/layer_widget.cpp
+++ b/ui/layers/layer_widget.cpp
@@ -281,7 +281,7 @@ void LayerStackWidget::BackgroundWidget::paintEvent(QPaintEvent *e) {
 		// in the transparent special layer cache corners after filling special layer
 		// rect above its cache with alpha_current opacity.
 		const auto region = QRegion(bg) - specialLayerBox;
-		for (const auto rect : region) {
+		for (const auto &rect : region) {
 			p.fillRect(rect, st::layerBg);
 		}
 		p.setOpacity((bgOpacity - overSpecialOpacity) / (1. - (overSpecialOpacity * st::layerBg->c.alphaF())));
diff --git a/ui/widgets/menu/menu_action.cpp b/ui/widgets/menu/menu_action.cpp
index 2c3601d..2f11c73 100644
--- a/ui/widgets/menu/menu_action.cpp
+++ b/ui/widgets/menu/menu_action.cpp
@@ -18,7 +18,7 @@ namespace {
 	auto result = TextWithEntities();
 	result.text.reserve(text.size());
 	auto afterAmpersand = false;
-	for (const auto ch : text) {
+	for (const auto &ch : text) {
 		if (afterAmpersand) {
 			afterAmpersand = false;
 			if (ch == '&') {
diff --git a/ui/widgets/popup_menu.cpp b/ui/widgets/popup_menu.cpp
index 23c1a50..3ecbfbb 100644
--- a/ui/widgets/popup_menu.cpp
+++ b/ui/widgets/popup_menu.cpp
@@ -37,7 +37,7 @@ PopupMenu::PopupMenu(QWidget *parent, QMenu *menu, const style::PopupMenu &st)
 , _menu(this, menu, _st.menu) {
 	init();
 
-	for (const auto action : actions()) {
+	for (const auto &action : actions()) {
 		if (const auto submenu = action->menu()) {
 			_submenus.emplace(
 				action,