diff --git a/src/main.cpp b/src/main.cpp
index 8b93c81..982f379 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -22,7 +22,7 @@ int main(int argc, char *argv[])
   a.setQuitOnLastWindowClosed(false);
 
   {
-    AppTranslator appTranslator({"screentranslator"});
+    service::AppTranslator appTranslator({"screentranslator"});
     appTranslator.retranslate();
   }
 
@@ -35,7 +35,7 @@ int main(int argc, char *argv[])
     parser.process(a);
   }
 
-  SingleApplication guard;
+  service::SingleApplication guard;
   if (!guard.isValid())
     return 1;
 
diff --git a/src/service/apptranslator.cpp b/src/service/apptranslator.cpp
index bd1c1c5..a32e0e9 100644
--- a/src/service/apptranslator.cpp
+++ b/src/service/apptranslator.cpp
@@ -4,6 +4,8 @@
 #include <QLibraryInfo>
 #include <QTranslator>
 
+namespace service
+{
 AppTranslator::AppTranslator(const QStringList &translationFiles)
   : translationFiles_(translationFiles)
 {
@@ -49,3 +51,5 @@ QStringList AppTranslator::searchPaths() const
       QLatin1String(":/translations"),
   };
 }
+
+}  // namespace service
diff --git a/src/service/apptranslator.h b/src/service/apptranslator.h
index 065b4c1..d2c0086 100644
--- a/src/service/apptranslator.h
+++ b/src/service/apptranslator.h
@@ -2,6 +2,8 @@
 
 #include <QStringList>
 
+namespace service
+{
 class AppTranslator
 {
 public:
@@ -13,3 +15,5 @@ private:
   QStringList searchPaths() const;
   QStringList translationFiles_;
 };
+
+}  // namespace service
diff --git a/src/service/globalaction.cpp b/src/service/globalaction.cpp
index e7a95e4..4a6abdb 100644
--- a/src/service/globalaction.cpp
+++ b/src/service/globalaction.cpp
@@ -3,6 +3,8 @@
 
 #include <QApplication>
 
+namespace service
+{
 QHash<QPair<quint32, quint32>, QAction *> GlobalAction::actions_;
 
 void GlobalAction::init()
@@ -70,12 +72,15 @@ void GlobalAction::triggerHotKey(quint32 nativeKey, quint32 nativeMods)
   if (action && action->isEnabled())
     action->activate(QAction::Trigger);
 }
+}  // namespace service
 
 #ifdef Q_OS_LINUX
 #include <X11/Xlib.h>
 #include <xcb/xcb_event.h>
 #include <QX11Info>
 
+namespace service
+{
 static bool error = false;
 
 static int customHandler(Display *display, XErrorEvent *event)
@@ -169,6 +174,8 @@ quint32 GlobalAction::nativeModifiers(Qt::KeyboardModifiers modifiers)
 #ifdef Q_OS_WIN
 #include <qt_windows.h>
 
+namespace service
+{
 bool GlobalAction::registerHotKey(quint32 nativeKey, quint32 nativeMods)
 {
   return RegisterHotKey(0, nativeMods ^ nativeKey, nativeMods, nativeKey);
@@ -319,6 +326,8 @@ quint32 GlobalAction::nativeModifiers(Qt::KeyboardModifiers modifiers)
 #ifdef Q_OS_MAC
 #include <Carbon/Carbon.h>
 
+namespace service
+{
 static bool isInited = false;
 static QHash<QPair<quint32, quint32>, EventHotKeyRef> hotkeyRefs;
 
@@ -479,3 +488,5 @@ quint32 GlobalAction::nativeModifiers(Qt::KeyboardModifiers modifiers)
 }
 
 #endif  // ifdef Q_OS_MAC
+
+}  // namespace service
diff --git a/src/service/globalaction.h b/src/service/globalaction.h
index 3356c14..90fba80 100644
--- a/src/service/globalaction.h
+++ b/src/service/globalaction.h
@@ -5,6 +5,8 @@
 #include <QAbstractNativeEventFilter>
 #include <QAction>
 
+namespace service
+{
 class GlobalAction : public QAbstractNativeEventFilter
 {
 public:
@@ -27,3 +29,5 @@ private:
 
   friend struct ActionAdapter;
 };
+
+}  // namespace service
diff --git a/src/service/singleapplication.cpp b/src/service/singleapplication.cpp
index e68c80b..66cd6a9 100644
--- a/src/service/singleapplication.cpp
+++ b/src/service/singleapplication.cpp
@@ -15,6 +15,8 @@ static QString fileName(const QString &baseName)
          QDir::separator() + name + QLatin1String(".lock");
 }
 
+namespace service
+{
 SingleApplication::SingleApplication(const QString &baseName)
   : lockFile_(fileName(baseName))
 {
@@ -29,3 +31,5 @@ bool SingleApplication::isValid() const
 {
   return lockFile_.isLocked();
 }
+
+}  // namespace service
diff --git a/src/service/singleapplication.h b/src/service/singleapplication.h
index 131688f..8312148 100644
--- a/src/service/singleapplication.h
+++ b/src/service/singleapplication.h
@@ -2,6 +2,8 @@
 
 #include <QLockFile>
 
+namespace service
+{
 class SingleApplication
 {
 public:
@@ -12,3 +14,5 @@ public:
 private:
   QLockFile lockFile_;
 };
+
+}  // namespace service
diff --git a/src/service/widgetstate.cpp b/src/service/widgetstate.cpp
index 94d7291..69d7e44 100644
--- a/src/service/widgetstate.cpp
+++ b/src/service/widgetstate.cpp
@@ -8,6 +8,8 @@
 #include <QSplitter>
 #include <QTableView>
 
+namespace service
+{
 namespace
 {
 enum class Action { Save, Restore };
@@ -116,3 +118,5 @@ void WidgetState::restore(QWidget *widget)
   SOFT_ASSERT(!widget->objectName().isEmpty(), return );
   apply(widget, Action::Restore);
 }
+
+}  // namespace service
diff --git a/src/service/widgetstate.h b/src/service/widgetstate.h
index 2c46245..3fe8904 100644
--- a/src/service/widgetstate.h
+++ b/src/service/widgetstate.h
@@ -2,6 +2,8 @@
 
 #include <QObject>
 
+namespace service
+{
 class WidgetState : public QObject
 {
 public:
@@ -12,3 +14,5 @@ public:
   static void save(QWidget *widget);
   static void restore(QWidget *widget);
 };
+
+}  // namespace service
diff --git a/src/settingseditor.cpp b/src/settingseditor.cpp
index b2ac2cf..31257c5 100644
--- a/src/settingseditor.cpp
+++ b/src/settingseditor.cpp
@@ -88,7 +88,7 @@ SettingsEditor::SettingsEditor(Manager &manager, update::Loader &updater)
   connect(ui->applyUpdates, &QPushButton::clicked,  //
           &updater_, &update::Loader::applyUserActions);
 
-  new WidgetState(this);
+  new service::WidgetState(this);
 }
 
 SettingsEditor::~SettingsEditor()
diff --git a/src/translate/translator.cpp b/src/translate/translator.cpp
index ad4c444..416cda0 100644
--- a/src/translate/translator.cpp
+++ b/src/translate/translator.cpp
@@ -89,7 +89,7 @@ Translator::Translator(Manager &manager, const Settings &settings)
 
   view_->setMinimumSize(200, 200);
 
-  new WidgetState(this);
+  new service::WidgetState(this);
 }
 
 Translator::~Translator() = default;
diff --git a/src/trayicon.cpp b/src/trayicon.cpp
index 4b8a356..25b004a 100644
--- a/src/trayicon.cpp
+++ b/src/trayicon.cpp
@@ -7,6 +7,8 @@
 #include <QMenu>
 #include <QTimer>
 
+using GlobalAction = service::GlobalAction;
+
 TrayIcon::TrayIcon(Manager &manager, const Settings &settings)
   : manager_(manager)
   , settings_(settings)