diff --git a/src/analyzer/analyzercontainer.cpp b/src/analyzer/analyzercontainer.cpp
index ff0c4a763..1c341e5aa 100644
--- a/src/analyzer/analyzercontainer.cpp
+++ b/src/analyzer/analyzercontainer.cpp
@@ -23,13 +23,12 @@
 #include <QWidget>
 #include <QVariant>
 #include <QString>
-#include <QMenu>
-#include <QAction>
-#include <QActionGroup>
 #include <QTimer>
 #include <QBoxLayout>
 #include <QLayout>
-#include <QSignalMapper>
+#include <QMenu>
+#include <QAction>
+#include <QActionGroup>
 #include <QSettings>
 #include <QtEvents>
 #include <QtDebug>
@@ -60,8 +59,6 @@ AnalyzerContainer::AnalyzerContainer(QWidget *parent)
       context_menu_framerate_(new QMenu(tr("Framerate"), this)),
       group_(new QActionGroup(this)),
       group_framerate_(new QActionGroup(this)),
-      mapper_(new QSignalMapper(this)),
-      mapper_framerate_(new QSignalMapper(this)),
       visualisation_action_(nullptr),
       double_click_timer_(new QTimer(this)),
       ignore_next_click_(false),
@@ -77,7 +74,6 @@ AnalyzerContainer::AnalyzerContainer(QWidget *parent)
   AddFramerate(tr("Medium (%1 fps)").arg(kMediumFramerate), kMediumFramerate);
   AddFramerate(tr("High (%1 fps)").arg(kHighFramerate), kHighFramerate);
   AddFramerate(tr("Super high (%1 fps)").arg(kSuperHighFramerate), kSuperHighFramerate);
-  connect(mapper_framerate_, SIGNAL(mapped(int)), SLOT(ChangeFramerate(int)));
 
   context_menu_->addMenu(context_menu_framerate_);
   context_menu_->addSeparator();
@@ -87,7 +83,6 @@ AnalyzerContainer::AnalyzerContainer(QWidget *parent)
   AddAnalyzerType<Rainbow::NyanCatAnalyzer>();
   AddAnalyzerType<Rainbow::RainbowDashAnalyzer>();
 
-  connect(mapper_, SIGNAL(mapped(int)), SLOT(ChangeAnalyzer(int)));
   disable_action_ = context_menu_->addAction(tr("No analyzer"), this, SLOT(DisableAnalyzer()));
   disable_action_->setCheckable(true);
   group_->addAction(disable_action_);
@@ -250,10 +245,10 @@ void AnalyzerContainer::Save() {
 
 void AnalyzerContainer::AddFramerate(const QString& name, int framerate) {
 
-  QAction *action = context_menu_framerate_->addAction(name, mapper_framerate_, SLOT(map()));
-  mapper_framerate_->setMapping(action, framerate);
+  QAction *action = context_menu_framerate_->addAction(name);
   group_framerate_->addAction(action);
   framerate_list_ << framerate;
   action->setCheckable(true);
+  connect(action, &QAction::triggered, [this, framerate]() { ChangeFramerate(framerate); } );
 
 }
diff --git a/src/analyzer/analyzercontainer.h b/src/analyzer/analyzercontainer.h
index 17872ddcf..25b835b0e 100644
--- a/src/analyzer/analyzercontainer.h
+++ b/src/analyzer/analyzercontainer.h
@@ -24,7 +24,6 @@
 
 #include <stdbool.h>
 
-#include <QObject>
 #include <QWidget>
 #include <QList>
 #include <QString>
@@ -32,12 +31,10 @@
 #include <QMenu>
 #include <QAction>
 #include <QActionGroup>
-#include <QSignalMapper>
-#include <QTimer>
-#include <QtEvents>
 
 #include "engine/engine_fwd.h"
 
+class QTimer;
 class QMouseEvent;
 class QWheelEvent;
 
@@ -90,8 +87,6 @@ signals:
   QMenu *context_menu_framerate_;
   QActionGroup *group_;
   QActionGroup *group_framerate_;
-  QSignalMapper *mapper_;
-  QSignalMapper *mapper_framerate_;
 
   QList<const QMetaObject*> analyzer_types_;
   QList<int> framerate_list_;
@@ -110,14 +105,16 @@ signals:
 
 template <typename T>
 void AnalyzerContainer::AddAnalyzerType() {
+
   int id = analyzer_types_.count();
   analyzer_types_ << &T::staticMetaObject;
 
-  QAction *action = context_menu_->addAction(tr(T::kName), mapper_, SLOT(map()));
+  QAction *action = context_menu_->addAction(tr(T::kName));
   group_->addAction(action);
-  mapper_->setMapping(action, id);
   action->setCheckable(true);
   actions_ << action;
+  connect(action, &QAction::triggered, [this, id]() { ChangeAnalyzer(id); } );
+
 }
 
 #endif  // ANALYZERCONTAINER_H
diff --git a/src/collection/collectionfilterwidget.cpp b/src/collection/collectionfilterwidget.cpp
index 2f6194db3..efd151a72 100644
--- a/src/collection/collectionfilterwidget.cpp
+++ b/src/collection/collectionfilterwidget.cpp
@@ -37,7 +37,6 @@
 #include <QTimer>
 #include <QMenu>
 #include <QSettings>
-#include <QSignalMapper>
 #include <QToolButton>
 #include <QtEvents>
 
@@ -87,20 +86,12 @@ CollectionFilterWidget::CollectionFilterWidget(QWidget *parent)
   filter_age_menu_ = new QMenu(tr("Show"), this);
   filter_age_menu_->addActions(filter_age_group->actions());
 
-  filter_age_mapper_ = new QSignalMapper(this);
-  filter_age_mapper_->setMapping(ui_->filter_age_all, -1);
-  filter_age_mapper_->setMapping(ui_->filter_age_today, 60 * 60 * 24);
-  filter_age_mapper_->setMapping(ui_->filter_age_week, 60 * 60 * 24 * 7);
-  filter_age_mapper_->setMapping(ui_->filter_age_month, 60 * 60 * 24 * 30);
-  filter_age_mapper_->setMapping(ui_->filter_age_three_months, 60 * 60 * 24 * 30 * 3);
-  filter_age_mapper_->setMapping(ui_->filter_age_year, 60 * 60 * 24 * 365);
-
-  connect(ui_->filter_age_all, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
-  connect(ui_->filter_age_today, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
-  connect(ui_->filter_age_week, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
-  connect(ui_->filter_age_month, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
-  connect(ui_->filter_age_three_months, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
-  connect(ui_->filter_age_year, SIGNAL(triggered()), filter_age_mapper_, SLOT(map()));
+  filter_ages_[ui_->filter_age_all] = -1;
+  filter_ages_[ui_->filter_age_today] = 60 * 60 * 24;
+  filter_ages_[ui_->filter_age_week] = 60 * 60 * 24 * 7;
+  filter_ages_[ui_->filter_age_month] = 60 * 60 * 24 * 30;
+  filter_ages_[ui_->filter_age_three_months] = 60 * 60 * 24 * 30 * 3;
+  filter_ages_[ui_->filter_age_year] = 60 * 60 * 24 * 365;
 
   // "Group by ..."
   group_by_group_ = CreateGroupByActions(this);
@@ -244,7 +235,9 @@ void CollectionFilterWidget::SetCollectionModel(CollectionModel *model) {
     disconnect(model_, 0, this, 0);
     disconnect(model_, 0, group_by_dialog_.get(), 0);
     disconnect(group_by_dialog_.get(), 0, model_, 0);
-    disconnect(filter_age_mapper_, 0, model_, 0);
+    for (QAction *action : filter_ages_.keys()) {
+      disconnect(action, &QAction::triggered, model_, 0);
+    }
   }
 
   model_ = model;
@@ -253,7 +246,11 @@ void CollectionFilterWidget::SetCollectionModel(CollectionModel *model) {
   connect(model_, SIGNAL(GroupingChanged(CollectionModel::Grouping)), group_by_dialog_.get(), SLOT(CollectionGroupingChanged(CollectionModel::Grouping)));
   connect(model_, SIGNAL(GroupingChanged(CollectionModel::Grouping)), SLOT(GroupingChanged(CollectionModel::Grouping)));
   connect(group_by_dialog_.get(), SIGNAL(Accepted(CollectionModel::Grouping)), model_, SLOT(SetGroupBy(CollectionModel::Grouping)));
-  connect(filter_age_mapper_, SIGNAL(mapped(int)), model_, SLOT(SetFilterAge(int)));
+
+  for (QAction *action : filter_ages_.keys()) {
+    int age = filter_ages_[action];
+    connect(action, &QAction::triggered, [this, age]() { model_->SetFilterAge(age); } );
+  }
 
   // Load settings
   if (!settings_group_.isEmpty()) {
diff --git a/src/collection/collectionfilterwidget.h b/src/collection/collectionfilterwidget.h
index 0b6aacdfd..508fb87dd 100644
--- a/src/collection/collectionfilterwidget.h
+++ b/src/collection/collectionfilterwidget.h
@@ -28,17 +28,17 @@
 
 #include <QWidget>
 #include <QObject>
+#include <QMap>
 #include <QString>
-#include <QMenu>
-#include <QSignalMapper>
-#include <QTimer>
-#include <QAction>
-#include <QActionGroup>
 #include <QtEvents>
 
 #include "collectionquery.h"
 #include "collectionmodel.h"
 
+class QTimer;
+class QMenu;
+class QAction;
+class QActionGroup;
 class QKeyEvent;
 
 class GroupByDialog;
@@ -120,7 +120,7 @@ signals:
   QMenu *group_by_menu_;
   QMenu *collection_menu_;
   QActionGroup *group_by_group_;
-  QSignalMapper *filter_age_mapper_;
+  QMap<QAction*, int> filter_ages_;
 
   QTimer *filter_delay_;
 
@@ -129,6 +129,7 @@ signals:
 
   QString settings_group_;
   QString settings_prefix_;
+
 };
 
 #endif  // COLLECTIONFILTERWIDGET_H
diff --git a/src/globalshortcuts/globalshortcuts.h b/src/globalshortcuts/globalshortcuts.h
index aba480d82..2f84e7c39 100644
--- a/src/globalshortcuts/globalshortcuts.h
+++ b/src/globalshortcuts/globalshortcuts.h
@@ -32,7 +32,6 @@
 #include <QString>
 #include <QAction>
 #include <QShortcut>
-#include <QSignalMapper>
 #include <QKeySequence>
 #include <QSettings>
 
diff --git a/src/organise/organisedialog.cpp b/src/organise/organisedialog.cpp
index 5ce4d8e8b..4b36c6c82 100644
--- a/src/organise/organisedialog.cpp
+++ b/src/organise/organisedialog.cpp
@@ -46,7 +46,6 @@
 #include <QGroupBox>
 #include <QListWidget>
 #include <QPushButton>
-#include <QSignalMapper>
 #include <QStackedWidget>
 #include <QToolButton>
 #include <QFlags>
@@ -124,14 +123,12 @@ OrganiseDialog::OrganiseDialog(TaskManager *task_manager, CollectionBackend *bac
 
   // Build the insert menu
   QMenu *tag_menu = new QMenu(this);
-  QSignalMapper *tag_mapper = new QSignalMapper(this);
   for (const QString &title : tag_titles) {
-    QAction *action = tag_menu->addAction(title, tag_mapper, SLOT(map()));
-    tag_mapper->setMapping(action, tags[title]);
+    QAction *action = tag_menu->addAction(title);
+    QString tag = tags[title];
+    connect(action, &QAction::triggered, [this, tag]() { InsertTag(tag); } );
   }
 
-  connect(tag_mapper, SIGNAL(mapped(QString)), SLOT(InsertTag(QString)));
-
   ui_->insert->setMenu(tag_menu);
 
   QSettings s;
diff --git a/src/playlist/playlistheader.cpp b/src/playlist/playlistheader.cpp
index e303b1f3e..1278982e9 100644
--- a/src/playlist/playlistheader.cpp
+++ b/src/playlist/playlistheader.cpp
@@ -23,13 +23,11 @@
 #include <stdbool.h>
 
 #include <QWidget>
-#include <QAbstractItemModel>
 #include <QFlags>
-#include <QMenu>
-#include <QSignalMapper>
 #include <QVariant>
 #include <QString>
 #include <QtAlgorithms>
+#include <QMenu>
 #include <QAction>
 #include <QActionGroup>
 #include <QContextMenuEvent>
@@ -41,9 +39,7 @@
 PlaylistHeader::PlaylistHeader(Qt::Orientation orientation, PlaylistView *view, QWidget *parent)
     : StretchHeaderView(orientation, parent),
       view_(view),
-      menu_(new QMenu(this)),
-      show_mapper_(new QSignalMapper(this))
-{
+      menu_(new QMenu(this)) {
 
   hide_action_ = menu_->addAction(tr("&Hide..."), this, SLOT(HideCurrent()));
   stretch_action_ = menu_->addAction(tr("&Stretch columns to fit window"), this, SLOT(ToggleStretchEnabled()));
@@ -69,7 +65,6 @@ PlaylistHeader::PlaylistHeader(Qt::Orientation orientation, PlaylistView *view,
   stretch_action_->setCheckable(true);
   stretch_action_->setChecked(is_stretch_enabled());
 
-  connect(show_mapper_, SIGNAL(mapped(int)), SLOT(ToggleVisible(int)));
   connect(this, SIGNAL(StretchEnabledChanged(bool)), stretch_action_, SLOT(setChecked(bool)));
 
 }
@@ -112,12 +107,12 @@ void PlaylistHeader::AddColumnAction(int index) {
 
   QString title(model()->headerData(index, Qt::Horizontal).toString());
 
-  QAction *action = menu_->addAction(title, show_mapper_, SLOT(map()));
+  QAction *action = menu_->addAction(title);
   action->setCheckable(true);
   action->setChecked(!isSectionHidden(index));
   show_actions_ << action;
 
-  show_mapper_->setMapping(action, index);
+  connect(action, &QAction::triggered, [this, index]() { ToggleVisible(index); } );
 
 }
 
diff --git a/src/playlist/playlistheader.h b/src/playlist/playlistheader.h
index c1191d538..ef58e6de9 100644
--- a/src/playlist/playlistheader.h
+++ b/src/playlist/playlistheader.h
@@ -28,14 +28,13 @@
 #include <QObject>
 #include <QWidget>
 #include <QList>
-#include <QAction>
-#include <QMenu>
-#include <QSignalMapper>
-#include <QString>
 #include <QtEvents>
 
 #include "widgets/stretchheaderview.h"
 
+class QMenu;
+class QAction;
+
 class PlaylistView;
 
 class PlaylistHeader : public StretchHeaderView {
@@ -74,7 +73,6 @@ class PlaylistHeader : public StretchHeaderView {
   QAction *align_right_action_;
   QList<QAction*> show_actions_;
 
-  QSignalMapper *show_mapper_;
 };
 
 #endif  // PLAYLISTHEADER_H
diff --git a/src/widgets/fancytabwidget.cpp b/src/widgets/fancytabwidget.cpp
index 87dad0c18..32ff7e2d3 100644
--- a/src/widgets/fancytabwidget.cpp
+++ b/src/widgets/fancytabwidget.cpp
@@ -32,22 +32,22 @@
 #include <QHash>
 #include <QString>
 #include <QIcon>
-#include <QMenu>
 #include <QPainter>
 #include <QColor>
 #include <QRect>
 #include <QFont>
-#include <QSignalMapper>
 #include <QStylePainter>
 #include <QTimer>
 #include <QLayout>
 #include <QVBoxLayout>
-#include <QMouseEvent>
-#include <QSettings>
 #include <QSize>
 #include <QPoint>
 #include <QTransform>
+#include <QMenu>
 #include <QAction>
+#include <QActionGroup>
+#include <QSettings>
+#include <QMouseEvent>
 
 const QSize FancyTabWidget::IconSize_LargeSidebar = QSize(24, 24);
 const QSize FancyTabWidget::IconSize_SmallSidebar = QSize(22, 22);
@@ -536,12 +536,11 @@ void FancyTabWidget::SetMode(FancyTabWidget::Mode mode) {
 
 }
 
-void FancyTabWidget::addMenuItem(QSignalMapper* mapper, QActionGroup* group, const QString& text, Mode mode) {
+void FancyTabWidget::addMenuItem(QActionGroup* group, const QString& text, Mode mode) {
 
   QAction* action = group->addAction(text);
   action->setCheckable(true);
-  mapper->setMapping(action, mode);
-  connect(action, SIGNAL(triggered()), mapper, SLOT(map()));
+  connect(action, &QAction::triggered, [this, mode]() { SetMode(mode); } );
 
   if (mode == mode_) action->setChecked(true);
 
@@ -550,18 +549,14 @@ void FancyTabWidget::addMenuItem(QSignalMapper* mapper, QActionGroup* group, con
 void FancyTabWidget::contextMenuEvent(QContextMenuEvent* e) {
 
   if (!menu_) {
-
     menu_ = new QMenu(this);
-    QSignalMapper* mapper = new QSignalMapper(this);
     QActionGroup* group = new QActionGroup(this);
-    addMenuItem(mapper, group, tr("Large sidebar"), Mode_LargeSidebar);
-    addMenuItem(mapper, group, tr("Small sidebar"), Mode_SmallSidebar);
-    addMenuItem(mapper, group, tr("Plain sidebar"), Mode_PlainSidebar);
-    addMenuItem(mapper, group, tr("Tabs on top"), Mode_Tabs);
-    addMenuItem(mapper, group, tr("Icons on top"), Mode_IconOnlyTabs);
+    addMenuItem(group, tr("Large sidebar"), Mode_LargeSidebar);
+    addMenuItem(group, tr("Small sidebar"), Mode_SmallSidebar);
+    addMenuItem(group, tr("Plain sidebar"), Mode_PlainSidebar);
+    addMenuItem(group, tr("Tabs on top"), Mode_Tabs);
+    addMenuItem(group, tr("Icons on top"), Mode_IconOnlyTabs);
     menu_->addActions(group->actions());
-    connect(mapper, SIGNAL(mapped(int)), SLOT(SetMode(int)));
-
   }
 
   menu_->popup(e->globalPos());
diff --git a/src/widgets/fancytabwidget.h b/src/widgets/fancytabwidget.h
index c6d440530..42d77ab5d 100644
--- a/src/widgets/fancytabwidget.h
+++ b/src/widgets/fancytabwidget.h
@@ -24,18 +24,16 @@
 
 #include <memory>
 
-#include <QObject>
 #include <QTabWidget>
-#include <QWidget>
-#include <QActionGroup>
-#include <QMenu>
-#include <QSignalMapper>
+#include <QMap>
 #include <QString>
 #include <QIcon>
 #include <QPixmap>
 #include <QSize>
 #include <QtEvents>
 
+class QMenu;
+class QActionGroup;
 class TabData;
 
 namespace Core {
@@ -95,7 +93,7 @@ class FancyTabWidget : public QTabWidget {
     void paintEvent(QPaintEvent *);
     void contextMenuEvent(QContextMenuEvent* e);
   private:
-    void addMenuItem(QSignalMapper* mapper, QActionGroup* group, const QString& text, Mode mode);
+    void addMenuItem(QActionGroup* group, const QString& text, Mode mode);
 
     QPixmap background_pixmap_;
     QMenu* menu_;
diff --git a/src/widgets/loginstatewidget.h b/src/widgets/loginstatewidget.h
index 7a5d7354a..a55ccf6ef 100644
--- a/src/widgets/loginstatewidget.h
+++ b/src/widgets/loginstatewidget.h
@@ -50,7 +50,7 @@ class LoginStateWidget : public QWidget {
 
  public slots:
   // Changes the "You are logged in/out" label, shows/hides any QGroupBoxes added with AddCredentialGroup.
-  void SetLoggedIn(State state, const QString &account_name = QString::null);
+  void SetLoggedIn(State state, const QString &account_name = QString());
 
   // Hides the "You are logged in/out" label completely.
   void HideLoggedInState();
diff --git a/src/widgets/playingwidget.cpp b/src/widgets/playingwidget.cpp
index a7aae7c3c..4b5495318 100644
--- a/src/widgets/playingwidget.cpp
+++ b/src/widgets/playingwidget.cpp
@@ -35,7 +35,6 @@
 #include <QPainter>
 #include <QPalette>
 #include <QBrush>
-#include <QSignalMapper>
 #include <QTextDocument>
 #include <QTimeLine>
 #include <QAction>
@@ -101,10 +100,8 @@ PlayingWidget::PlayingWidget(QWidget *parent)
 
   // Context menu
   QActionGroup *mode_group = new QActionGroup(this);
-  QSignalMapper *mode_mapper = new QSignalMapper(this);
-  connect(mode_mapper, SIGNAL(mapped(int)), SLOT(SetMode(int)));
-  CreateModeAction(SmallSongDetails, tr("Small album cover"), mode_group, mode_mapper);
-  CreateModeAction(LargeSongDetails, tr("Large album cover"), mode_group, mode_mapper);
+  CreateModeAction(SmallSongDetails, tr("Small album cover"), mode_group);
+  CreateModeAction(LargeSongDetails, tr("Large album cover"), mode_group);
   menu_->addActions(mode_group->actions());
 
   fit_cover_width_action_ = menu_->addAction(tr("Fit cover to width"));
@@ -200,12 +197,11 @@ QSize PlayingWidget::sizeHint() const {
   return QSize(cover_loader_options_.desired_height_, total_height_);
 }
 
-void PlayingWidget::CreateModeAction(Mode mode, const QString &text, QActionGroup *group, QSignalMapper *mapper) {
+void PlayingWidget::CreateModeAction(Mode mode, const QString &text, QActionGroup *group) {
 
   QAction *action = new QAction(text, group);
   action->setCheckable(true);
-  mapper->setMapping(action, mode);
-  connect(action, SIGNAL(triggered()), mapper, SLOT(map()));
+  connect(action, &QAction::triggered, [this, mode]() { SetMode(mode); } );
 
   if (mode == mode_) action->setChecked(true);
 
@@ -287,7 +283,7 @@ void PlayingWidget::SetImage(const QImage &image) {
     QSize psize(size());
     if (size().height() <= 0) psize.setHeight(total_height_);
     pixmap_previous_track_ = QPixmap(psize);
-    pixmap_previous_track_.fill(palette().background().color());
+    pixmap_previous_track_.fill(palette().window().color());
     pixmap_previous_track_opacity_ = 1.0;
     QPainter p(&pixmap_previous_track_);
     DrawContents(&p);
diff --git a/src/widgets/playingwidget.h b/src/widgets/playingwidget.h
index 33a7b5be8..70a07f3f9 100644
--- a/src/widgets/playingwidget.h
+++ b/src/widgets/playingwidget.h
@@ -31,24 +31,24 @@
 #include <QObject>
 #include <QWidget>
 #include <QString>
+#include <QUrl>
 #include <QImage>
 #include <QPixmap>
-#include <QPainter>
 #include <QSize>
-#include <QSignalMapper>
-#include <QTextDocument>
-#include <QTimeLine>
-#include <QAction>
-#include <QActionGroup>
 #include <QMenu>
 #include <QMovie>
-#include <QtEvents>
 
 #include "core/song.h"
 #include "covermanager/albumcoverloaderoptions.h"
 
 using std::unique_ptr;
 
+class QTimeLine;
+class QTextDocument;
+class QPainter;
+class QMenu;
+class QAction;
+class QActionGroup;
 class QContextMenuEvent;
 class QDragEnterEvent;
 class QDropEvent;
@@ -148,7 +148,7 @@ class PlayingWidget : public QWidget {
   std::unique_ptr<QMovie> spinner_animation_;
 
   void SetVisible(bool visible);
-  void CreateModeAction(Mode mode, const QString &text, QActionGroup *group, QSignalMapper *mapper);
+  void CreateModeAction(Mode mode, const QString &text, QActionGroup *group);
   void UpdateDetailsText();
   void UpdateHeight();
   void SetImage(const QImage &image);