diff --git a/ui/style/style_core.cpp b/ui/style/style_core.cpp
index 18a5bbb..3f9b003 100644
--- a/ui/style/style_core.cpp
+++ b/ui/style/style_core.cpp
@@ -29,6 +29,7 @@ auto PaletteChanges = rpl::event_stream<>();
 auto ShortAnimationRunning = rpl::variable<bool>(false);
 auto RunningShortAnimations = 0;
 auto ResolvedMonospaceFont = style::font();
+QString CustomMonospaceFont;
 
 std::vector<internal::ModuleBase*> &StyleModules() {
 	static auto result = std::vector<internal::ModuleBase*>();
@@ -51,6 +52,9 @@ void ResolveMonospaceFont() {
 			family = attempt;
 		}
 	};
+	if (!CustomMonospaceFont.isEmpty()) {
+		tryFont(CustomMonospaceFont);
+	}
 	tryFont("Consolas");
 	tryFont("Liberation Mono");
 	tryFont("Menlo");
@@ -65,6 +69,10 @@ void ResolveMonospaceFont() {
 
 } // namespace
 
+void SetMonospaceFont(const QString &familyName) {
+	CustomMonospaceFont = familyName;
+}
+
 void registerModule(ModuleBase *module) {
 	StyleModules().push_back(module);
 }
diff --git a/ui/style/style_core.h b/ui/style/style_core.h
index 62da03c..ce6ced5 100644
--- a/ui/style/style_core.h
+++ b/ui/style/style_core.h
@@ -25,6 +25,8 @@ public:
 
 };
 
+void SetMonospaceFont(const QString &familyName);
+
 void registerModule(ModuleBase *module);
 
 [[nodiscard]] QColor EnsureContrast(const QColor &over, const QColor &under);
diff --git a/ui/style/style_core_font.cpp b/ui/style/style_core_font.cpp
index cfe2111..ad3a9e3 100644
--- a/ui/style/style_core_font.cpp
+++ b/ui/style/style_core_font.cpp
@@ -121,8 +121,24 @@ QString FontTypeWindowsFallback[FontTypesCount] = {
 bool Started = false;
 QString Overrides[FontTypesCount];
 
+QString CustomMainFont;
+QString CustomSemiboldFont;
+bool CustomSemiboldIsBold = false;
+
 } // namespace
 
+void SetMainFont(const QString &familyName) {
+	CustomMainFont = familyName;
+}
+
+void SetSemiboldFont(const QString &familyName) {
+	CustomSemiboldFont = familyName;
+}
+
+void SetSemiboldIsBold(bool isBold) {
+	CustomSemiboldIsBold = isBold;
+}
+
 void StartFonts() {
 	if (Started) {
 		return;
@@ -164,6 +180,17 @@ void StartFonts() {
 		QFont::insertSubstitutions(name, list);
 	}
 #endif // Q_OS_MAC
+
+	if (!CustomMainFont.isEmpty() && ValidateFont(CustomMainFont)) {
+		Overrides[FontTypeRegular] = CustomMainFont;
+		Overrides[FontTypeRegularItalic] = CustomMainFont;
+		Overrides[FontTypeBold] = CustomMainFont;
+		Overrides[FontTypeBoldItalic] = CustomMainFont;
+	}
+	if (!CustomSemiboldFont.isEmpty() && ValidateFont(CustomSemiboldFont)) {
+		Overrides[FontTypeSemibold] = CustomSemiboldFont;
+		Overrides[FontTypeSemiboldItalic] = CustomSemiboldFont;
+	}
 }
 
 QString GetPossibleEmptyOverride(const QString &familyName, int32 flags) {
@@ -226,8 +253,8 @@ FontData::FontData(int size, uint32 flags, int family, Font *other)
 	f.setPixelSize(size);
 	if (_flags & FontBold) {
 		f.setBold(true);
-	//} else if (fontFamilies[family] == "Open Sans Semibold") {
-	//	f.setWeight(QFont::DemiBold);
+	} else if (fontFamilies[family] == "Open Sans Semibold" && CustomSemiboldIsBold) {
+		f.setBold(true);
 	}
 	f.setItalic(_flags & FontItalic);
 	f.setUnderline(_flags & FontUnderline);
diff --git a/ui/style/style_core_font.h b/ui/style/style_core_font.h
index cd97457..6fbf581 100644
--- a/ui/style/style_core_font.h
+++ b/ui/style/style_core_font.h
@@ -14,6 +14,10 @@
 namespace style {
 namespace internal {
 
+void SetMainFont(const QString &familyName);
+void SetSemiboldFont(const QString &familyName);
+void SetSemiboldIsBold(bool isBold);
+
 void StartFonts();
 [[nodiscard]] QString GetFontOverride(const QString &familyName, int32 flags = 0);