diff --git a/Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp b/Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp
index 51090e9594..cf849f3b54 100644
--- a/Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp
+++ b/Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp
@@ -782,7 +782,7 @@ void InnerWidget::paintPeerSearchResult(
 	QRect tr(nameleft, st::dialogsPadding.y() + st::msgNameFont->height + st::dialogsSkip, namewidth, st::dialogsTextFont->height);
 	p.setFont(st::dialogsTextFont);
 	QString username = peer->userName();
-	if (!active && username.toLower().startsWith(_peerSearchQuery)) {
+	if (!active && username.startsWith(_peerSearchQuery, Qt::CaseInsensitive)) {
 		auto first = '@' + username.mid(0, _peerSearchQuery.size());
 		auto second = username.mid(_peerSearchQuery.size());
 		auto w = st::dialogsTextFont->width(first);
diff --git a/Telegram/SourceFiles/platform/linux/specific_linux.cpp b/Telegram/SourceFiles/platform/linux/specific_linux.cpp
index ad7935575c..5fa8ecdb79 100644
--- a/Telegram/SourceFiles/platform/linux/specific_linux.cpp
+++ b/Telegram/SourceFiles/platform/linux/specific_linux.cpp
@@ -465,7 +465,7 @@ std::optional<bool> IsDarkMode() {
 
 	if (!themeName.has_value()) {
 		return std::nullopt;
-	} else if (themeName->toLower().contains(qsl("-dark"))) {
+	} else if (themeName->contains(qsl("-dark"), Qt::CaseInsensitive)) {
 		return true;
 	}