diff --git a/src/mixxxmainwindow.cpp b/src/mixxxmainwindow.cpp
index 03789c83bfb0..e03dcbb772d7 100644
--- a/src/mixxxmainwindow.cpp
+++ b/src/mixxxmainwindow.cpp
@@ -99,7 +99,7 @@ MixxxMainWindow::MixxxMainWindow(std::shared_ptr<mixxx::CoreServices> pCoreServi
 #endif
           m_pDeveloperToolsDlg(nullptr),
           m_pPrefDlg(nullptr),
-          m_toolTipsCfg(mixxx::preferences::constants::Tooltips::On) {
+          m_toolTipsCfg(mixxx::Tooltips::On) {
     DEBUG_ASSERT(pCoreServices);
     // These depend on the settings
 #ifdef __LINUX__
@@ -175,10 +175,10 @@ void MixxxMainWindow::initialize() {
     // Set the visibility of tooltips, default "1" = ON
     m_toolTipsCfg = pConfig->getValue(
             ConfigKey("[Controls]", "Tooltips"),
-            mixxx::preferences::constants::Tooltips::On);
+            mixxx::Tooltips::On);
 #ifdef MIXXX_USE_QOPENGL
     ToolTipQOpenGL::singleton().setActive(
-            m_toolTipsCfg == mixxx::preferences::constants::Tooltips::On);
+            m_toolTipsCfg == mixxx::Tooltips::On);
 #endif
 
 #ifdef __ENGINEPRIME__
@@ -1153,11 +1153,11 @@ void MixxxMainWindow::slotShowKeywheel(bool toggle) {
     }
 }
 
-void MixxxMainWindow::slotTooltipModeChanged(mixxx::preferences::constants::Tooltips tt) {
+void MixxxMainWindow::slotTooltipModeChanged(mixxx::Tooltips tt) {
     m_toolTipsCfg = tt;
 #ifdef MIXXX_USE_QOPENGL
     ToolTipQOpenGL::singleton().setActive(
-            m_toolTipsCfg == mixxx::preferences::constants::Tooltips::On);
+            m_toolTipsCfg == mixxx::Tooltips::On);
 #endif
 }
 
@@ -1260,14 +1260,14 @@ bool MixxxMainWindow::eventFilter(QObject* obj, QEvent* event) {
                         "DlgPreferences") {
             // return true for no tool tips
             switch (m_toolTipsCfg) {
-            case mixxx::preferences::constants::Tooltips::OnlyInLibrary:
+            case mixxx::Tooltips::OnlyInLibrary:
                 if (dynamic_cast<WBaseWidget*>(obj) != nullptr) {
                     return true;
                 }
                 break;
-            case mixxx::preferences::constants::Tooltips::On:
+            case mixxx::Tooltips::On:
                 break;
-            case mixxx::preferences::constants::Tooltips::Off:
+            case mixxx::Tooltips::Off:
                 return true;
             default:
                 DEBUG_ASSERT(!"m_toolTipsCfg value unknown");
diff --git a/src/mixxxmainwindow.h b/src/mixxxmainwindow.h
index d4011cb0efa1..d0b0f8952bef 100644
--- a/src/mixxxmainwindow.h
+++ b/src/mixxxmainwindow.h
@@ -50,8 +50,8 @@ class MixxxMainWindow : public QMainWindow {
     /// creates the menu_bar and inserts the file Menu
     void createMenuBar();
     void connectMenuBar();
-    void setInhibitScreensaver(mixxx::preferences::constants::ScreenSaver inhibit);
-    mixxx::preferences::constants::ScreenSaver getInhibitScreensaver();
+    void setInhibitScreensaver(mixxx::ScreenSaver inhibit);
+    mixxx::ScreenSaver getInhibitScreensaver();
 
     inline GuiTick* getGuiTick() { return m_pGuiTick; };
 
@@ -87,7 +87,7 @@ class MixxxMainWindow : public QMainWindow {
     void initializationProgressUpdate(int progress, const QString& serviceName);
 
   private slots:
-    void slotTooltipModeChanged(mixxx::preferences::constants::Tooltips tt);
+    void slotTooltipModeChanged(mixxx::Tooltips tt);
 
   signals:
     void skinLoaded();
@@ -148,9 +148,9 @@ class MixxxMainWindow : public QMainWindow {
     std::unique_ptr<mixxx::LibraryExporter> m_pLibraryExporter;
 #endif
 
-    mixxx::preferences::constants::Tooltips m_toolTipsCfg;
+    mixxx::Tooltips m_toolTipsCfg;
 
-    mixxx::preferences::constants::ScreenSaver m_inhibitScreensaver;
+    mixxx::ScreenSaver m_inhibitScreensaver;
 
     QSet<ControlObject*> m_skinCreatedControls;
 };
diff --git a/src/preferences/constants.h b/src/preferences/constants.h
index 7daab422f9ce..6666785b59d1 100644
--- a/src/preferences/constants.h
+++ b/src/preferences/constants.h
@@ -5,9 +5,9 @@
 
 namespace mixxx {
 
-namespace preferences {
+inline namespace preferences {
 
-namespace constants {
+inline namespace constants {
 Q_NAMESPACE
 
 // In order for this Q_NAMESPACE to work, all members of the namespace must
diff --git a/src/preferences/dialog/dlgpreferences.h b/src/preferences/dialog/dlgpreferences.h
index b9a3227bf4d4..828af871c27a 100644
--- a/src/preferences/dialog/dlgpreferences.h
+++ b/src/preferences/dialog/dlgpreferences.h
@@ -76,7 +76,7 @@ class DlgPreferences : public QDialog, public Ui::DlgPreferencesDlg {
     void resetToDefaults();
 
     void reloadUserInterface();
-    void tooltipModeChanged(mixxx::preferences::constants::Tooltips tooltipMode);
+    void tooltipModeChanged(mixxx::Tooltips tooltipMode);
     void menuBarAutoHideChanged();
 
   protected:
diff --git a/src/preferences/dialog/dlgprefinterface.cpp b/src/preferences/dialog/dlgprefinterface.cpp
index 3c171e702aec..3f9ab8385070 100644
--- a/src/preferences/dialog/dlgprefinterface.cpp
+++ b/src/preferences/dialog/dlgprefinterface.cpp
@@ -44,8 +44,6 @@ const bool kHideMenuBarDefault = true;
 
 } // namespace
 
-using namespace mixxx::preferences;
-
 DlgPrefInterface::DlgPrefInterface(
         QWidget* parent,
         std::shared_ptr<mixxx::ScreensaverManager> pScreensaverManager,
@@ -181,11 +179,11 @@ DlgPrefInterface::DlgPrefInterface(
     // Screensaver mode
     comboBoxScreensaver->clear();
     comboBoxScreensaver->addItem(tr("Allow screensaver to run"),
-            QVariant::fromValue(constants::ScreenSaver::Off));
+            QVariant::fromValue(mixxx::ScreenSaver::Off));
     comboBoxScreensaver->addItem(tr("Prevent screensaver from running"),
-            QVariant::fromValue((constants::ScreenSaver::On)));
+            QVariant::fromValue((mixxx::ScreenSaver::On)));
     comboBoxScreensaver->addItem(tr("Prevent screensaver while playing"),
-            QVariant::fromValue(constants::ScreenSaver::OnPlay));
+            QVariant::fromValue(mixxx::ScreenSaver::OnPlay));
 
     comboBoxScreensaver->setCurrentIndex(comboBoxScreensaver->findData(
             QVariant::fromValue(m_pScreensaverManager->status())));
@@ -195,19 +193,19 @@ DlgPrefInterface::DlgPrefInterface(
     if (CmdlineArgs::Instance().isQml()) {
         multiSamplingComboBox->clear();
         multiSamplingComboBox->addItem(tr("Disabled"),
-                QVariant::fromValue(constants::MultiSamplingMode::Disabled));
+                QVariant::fromValue(mixxx::MultiSamplingMode::Disabled));
         multiSamplingComboBox->addItem(tr("2x MSAA"),
-                QVariant::fromValue(constants::MultiSamplingMode::Two));
+                QVariant::fromValue(mixxx::MultiSamplingMode::Two));
         multiSamplingComboBox->addItem(tr("4x MSAA"),
-                QVariant::fromValue(constants::MultiSamplingMode::Four));
+                QVariant::fromValue(mixxx::MultiSamplingMode::Four));
         multiSamplingComboBox->addItem(tr("8x MSAA"),
-                QVariant::fromValue(constants::MultiSamplingMode::Eight));
+                QVariant::fromValue(mixxx::MultiSamplingMode::Eight));
         multiSamplingComboBox->addItem(tr("16x MSAA"),
-                QVariant::fromValue(constants::MultiSamplingMode::Sixteen));
+                QVariant::fromValue(mixxx::MultiSamplingMode::Sixteen));
 
-        m_multiSampling = m_pConfig->getValue<constants::MultiSamplingMode>(
+        m_multiSampling = m_pConfig->getValue<mixxx::MultiSamplingMode>(
                 ConfigKey(kPreferencesGroup, kMultiSamplingKey),
-                constants::MultiSamplingMode::Four);
+                mixxx::MultiSamplingMode::Four);
         int multiSamplingIndex = multiSamplingComboBox->findData(
                 QVariant::fromValue((m_multiSampling)));
         if (multiSamplingIndex != -1) {
@@ -215,7 +213,7 @@ DlgPrefInterface::DlgPrefInterface(
         } else {
             multiSamplingComboBox->setCurrentIndex(0); // Disabled
             m_pConfig->setValue(ConfigKey(kPreferencesGroup, kMultiSamplingKey),
-                    constants::MultiSamplingMode::Disabled);
+                    mixxx::MultiSamplingMode::Disabled);
         }
     } else
 #endif
@@ -354,12 +352,12 @@ void DlgPrefInterface::slotResetToDefaults() {
 
     // Inhibit the screensaver
     comboBoxScreensaver->setCurrentIndex(comboBoxScreensaver->findData(
-            QVariant::fromValue(constants::ScreenSaver::On)));
+            QVariant::fromValue(mixxx::ScreenSaver::On)));
 
 #ifdef MIXXX_USE_QML
     multiSamplingComboBox->setCurrentIndex(
             multiSamplingComboBox->findData(QVariant::fromValue(
-                    constants::MultiSamplingMode::Four))); // 4x MSAA
+                    mixxx::MultiSamplingMode::Four))); // 4x MSAA
 #endif
 
 #ifdef Q_OS_IOS
@@ -372,11 +370,11 @@ void DlgPrefInterface::slotResetToDefaults() {
 }
 
 void DlgPrefInterface::slotSetTooltips() {
-    m_tooltipMode = constants::Tooltips::On;
+    m_tooltipMode = mixxx::Tooltips::On;
     if (radioButtonTooltipsOff->isChecked()) {
-        m_tooltipMode = constants::Tooltips::Off;
+        m_tooltipMode = mixxx::Tooltips::Off;
     } else if (radioButtonTooltipsLibrary->isChecked()) {
-        m_tooltipMode = constants::Tooltips::OnlyInLibrary;
+        m_tooltipMode = mixxx::Tooltips::OnlyInLibrary;
     }
 }
 
@@ -479,17 +477,17 @@ void DlgPrefInterface::slotApply() {
 
     // screensaver mode update
     const auto screensaverComboBoxState =
-            comboBoxScreensaver->currentData().value<constants::ScreenSaver>();
+            comboBoxScreensaver->currentData().value<mixxx::ScreenSaver>();
     const auto screensaverConfiguredState = m_pScreensaverManager->status();
     if (screensaverComboBoxState != screensaverConfiguredState) {
         m_pScreensaverManager->setStatus(screensaverComboBoxState);
     }
 
 #ifdef MIXXX_USE_QML
-    constants::MultiSamplingMode multiSampling =
+    mixxx::MultiSamplingMode multiSampling =
             multiSamplingComboBox->currentData()
-                    .value<constants::MultiSamplingMode>();
-    m_pConfig->setValue<constants::MultiSamplingMode>(
+                    .value<mixxx::MultiSamplingMode>();
+    m_pConfig->setValue<mixxx::MultiSamplingMode>(
             ConfigKey(kPreferencesGroup, kMultiSamplingKey), multiSampling);
 #endif
 
@@ -520,20 +518,20 @@ void DlgPrefInterface::slotApply() {
 
 void DlgPrefInterface::loadTooltipPreferenceFromConfig() {
     const auto tooltipMode =
-            m_pConfig->getValue<constants::Tooltips>(ConfigKey(kControlsGroup, kTooltipsKey),
+            m_pConfig->getValue<mixxx::Tooltips>(ConfigKey(kControlsGroup, kTooltipsKey),
 #ifdef Q_OS_IOS
-                    constants::Tooltips::Off);
+                    mixxx::Tooltips::Off);
 #else
-                    constants::Tooltips::On);
+                    mixxx::Tooltips::On);
 #endif
     switch (tooltipMode) {
-    case constants::Tooltips::Off:
+    case mixxx::Tooltips::Off:
         radioButtonTooltipsOff->setChecked(true);
         break;
-    case constants::Tooltips::OnlyInLibrary:
+    case mixxx::Tooltips::OnlyInLibrary:
         radioButtonTooltipsLibrary->setChecked(true);
         break;
-    case constants::Tooltips::On:
+    case mixxx::Tooltips::On:
     default:
         radioButtonTooltipsLibraryAndSkin->setChecked(true);
         break;
diff --git a/src/preferences/dialog/dlgprefinterface.h b/src/preferences/dialog/dlgprefinterface.h
index 3744b81a770f..87016a62382a 100644
--- a/src/preferences/dialog/dlgprefinterface.h
+++ b/src/preferences/dialog/dlgprefinterface.h
@@ -45,7 +45,7 @@ class DlgPrefInterface : public DlgPreferencePage, public Ui::DlgPrefControlsDlg
   signals:
     void reloadUserInterface();
     void menuBarAutoHideChanged();
-    void tooltipModeChanged(mixxx::preferences::constants::Tooltips tooltipMode);
+    void tooltipModeChanged(mixxx::Tooltips tooltipMode);
 
   private:
     void notifyRebootNecessary();
@@ -69,10 +69,10 @@ class DlgPrefInterface : public DlgPreferencePage, public Ui::DlgPrefControlsDlg
     QString m_colorScheme;
     QString m_colorSchemeOnUpdate;
     QString m_localeOnUpdate;
-    mixxx::preferences::constants::MultiSamplingMode m_multiSampling;
-    mixxx::preferences::constants::Tooltips m_tooltipMode;
+    mixxx::MultiSamplingMode m_multiSampling;
+    mixxx::Tooltips m_tooltipMode;
     double m_dScaleFactor;
     double m_minScaleFactor;
     double m_dDevicePixelRatio;
-    mixxx::preferences::constants::ScreenSaver m_screensaverMode;
+    mixxx::ScreenSaver m_screensaverMode;
 };
diff --git a/src/qml/qmlconfigproxy.cpp b/src/qml/qmlconfigproxy.cpp
index 703cdb43cce3..811696faa3ef 100644
--- a/src/qml/qmlconfigproxy.cpp
+++ b/src/qml/qmlconfigproxy.cpp
@@ -39,7 +39,7 @@ QVariantList QmlConfigProxy::getTrackColorPalette() {
 int QmlConfigProxy::getMultiSamplingLevel() {
     return static_cast<int>(m_pConfig->getValue(
             ConfigKey(kPreferencesGroup, kMultiSamplingKey),
-            mixxx::preferences::constants::MultiSamplingMode::Disabled));
+            mixxx::MultiSamplingMode::Disabled));
 }
 
 // static
diff --git a/src/util/screensavermanager.cpp b/src/util/screensavermanager.cpp
index 626998769760..3ed68ad5d8be 100644
--- a/src/util/screensavermanager.cpp
+++ b/src/util/screensavermanager.cpp
@@ -9,26 +9,26 @@ ScreensaverManager::ScreensaverManager(UserSettingsPointer pConfig, QObject* pPa
         : QObject(pParent), m_pConfig(pConfig) {
     m_inhibitScreensaver =
             pConfig->getValue(ConfigKey("[Config]", "InhibitScreensaver"),
-                    mixxx::preferences::constants::ScreenSaver::On);
+                    mixxx::ScreenSaver::On);
     pConfig->setValue(ConfigKey("[Config]", "InhibitScreensaver"), m_inhibitScreensaver);
-    if (m_inhibitScreensaver == mixxx::preferences::constants::ScreenSaver::On) {
+    if (m_inhibitScreensaver == mixxx::ScreenSaver::On) {
         mixxx::ScreenSaverHelper::inhibit();
     }
 }
 
 ScreensaverManager::~ScreensaverManager() {
-    if (m_inhibitScreensaver != mixxx::preferences::constants::ScreenSaver::Off) {
+    if (m_inhibitScreensaver != mixxx::ScreenSaver::Off) {
         mixxx::ScreenSaverHelper::uninhibit();
     }
 }
 
-void ScreensaverManager::setStatus(mixxx::preferences::constants::ScreenSaver newInhibit) {
-    if (m_inhibitScreensaver != mixxx::preferences::constants::ScreenSaver::Off) {
+void ScreensaverManager::setStatus(mixxx::ScreenSaver newInhibit) {
+    if (m_inhibitScreensaver != mixxx::ScreenSaver::Off) {
         mixxx::ScreenSaverHelper::uninhibit();
     }
 
-    if (newInhibit == mixxx::preferences::constants::ScreenSaver::On ||
-            (newInhibit == mixxx::preferences::constants::ScreenSaver::OnPlay &&
+    if (newInhibit == mixxx::ScreenSaver::On ||
+            (newInhibit == mixxx::ScreenSaver::OnPlay &&
                     PlayerInfo::instance().getCurrentPlayingDeck() != -1)) {
         mixxx::ScreenSaverHelper::inhibit();
     }
@@ -37,7 +37,7 @@ void ScreensaverManager::setStatus(mixxx::preferences::constants::ScreenSaver ne
 }
 
 void ScreensaverManager::slotCurrentPlayingDeckChanged(int deck) {
-    if (m_inhibitScreensaver != mixxx::preferences::constants::ScreenSaver::OnPlay) {
+    if (m_inhibitScreensaver != mixxx::ScreenSaver::OnPlay) {
         return;
     }
     if (deck == -1) {
diff --git a/src/util/screensavermanager.h b/src/util/screensavermanager.h
index 0ddc8427bbb6..cf613bbe8ffc 100644
--- a/src/util/screensavermanager.h
+++ b/src/util/screensavermanager.h
@@ -13,9 +13,9 @@ class ScreensaverManager : public QObject {
     ScreensaverManager(UserSettingsPointer pConfig, QObject* pParent = nullptr);
     ~ScreensaverManager();
 
-    void setStatus(mixxx::preferences::constants::ScreenSaver status);
+    void setStatus(mixxx::ScreenSaver status);
 
-    mixxx::preferences::constants::ScreenSaver status() {
+    mixxx::ScreenSaver status() {
         return m_inhibitScreensaver;
     }
   public slots:
@@ -23,7 +23,7 @@ class ScreensaverManager : public QObject {
 
   private:
     const UserSettingsPointer m_pConfig;
-    mixxx::preferences::constants::ScreenSaver m_inhibitScreensaver;
+    mixxx::ScreenSaver m_inhibitScreensaver;
 };
 
 } // namespace mixxx