diff --git a/common/project.cpp b/common/project.cpp
index f3eb9bea..d3488709 100644
--- a/common/project.cpp
+++ b/common/project.cpp
@@ -73,7 +73,7 @@ Project::Project(bool IsPreview)
 	mModels.emplace_back(mActiveModel);
 
 	if (!mIsPreview && gMainWindow)
-		QObject::connect(&mFileWatcher, SIGNAL(fileChanged(const QString&)), gMainWindow, SLOT(ProjectFileChanged(const QString&)));
+		QObject::connect(&mFileWatcher, &QFileSystemWatcher::fileChanged, gMainWindow, &lcMainWindow::ProjectFileChanged);
 }
 
 Project::~Project()
diff --git a/qt/lc_qeditgroupsdialog.cpp b/qt/lc_qeditgroupsdialog.cpp
index e696ceba..1fb28e30 100644
--- a/qt/lc_qeditgroupsdialog.cpp
+++ b/qt/lc_qeditgroupsdialog.cpp
@@ -14,11 +14,13 @@ lcQEditGroupsDialog::lcQEditGroupsDialog(QWidget* Parent, const QMap<lcPiece*, l
 	ui = new Ui::lcQEditGroupsDialog;
 
 	ui->setupUi(this);
-	connect(ui->treeWidget,SIGNAL(itemClicked(QTreeWidgetItem *,int)), this, SLOT(onItemClicked(QTreeWidgetItem *,int)));
-	connect(ui->treeWidget,SIGNAL(itemDoubleClicked(QTreeWidgetItem *,int)), this, SLOT(onItemDoubleClicked(QTreeWidgetItem *,int)));
+
+	connect(ui->treeWidget, &QTreeWidget::itemClicked, this, &lcQEditGroupsDialog::onItemClicked);
+	connect(ui->treeWidget, &QTreeWidget::itemDoubleClicked, this, &lcQEditGroupsDialog::onItemDoubleClicked);
 
 	QPushButton *newGroup = ui->buttonBox->addButton(tr("New Group"), QDialogButtonBox::ActionRole);
-	connect(newGroup, SIGNAL(clicked()), this, SLOT(on_newGroup_clicked()));
+
+	connect(newGroup, &QPushButton::clicked, this, &lcQEditGroupsDialog::on_newGroup_clicked);
 
 	AddChildren(ui->treeWidget->invisibleRootItem(), nullptr);
 	ui->treeWidget->expandAll();
diff --git a/qt/lc_qpreferencesdialog.cpp b/qt/lc_qpreferencesdialog.cpp
index 09531b0c..212f21b7 100644
--- a/qt/lc_qpreferencesdialog.cpp
+++ b/qt/lc_qpreferencesdialog.cpp
@@ -52,12 +52,12 @@ lcQPreferencesDialog::lcQPreferencesDialog(QWidget* Parent, lcPreferencesDialogO
 	connect(ui->LightColorButton, &QToolButton::clicked, this, &lcQPreferencesDialog::ColorButtonClicked);
 	connect(ui->ControlPointColorButton, &QToolButton::clicked, this, &lcQPreferencesDialog::ColorButtonClicked);
 	connect(ui->ControlPointFocusedColorButton, &QToolButton::clicked, this, &lcQPreferencesDialog::ColorButtonClicked);
-	connect(ui->categoriesTree, SIGNAL(itemSelectionChanged()), this, SLOT(updateParts()));
+	connect(ui->categoriesTree, &QTreeWidget::itemSelectionChanged, this, &lcQPreferencesDialog::updateParts);
 	ui->shortcutEdit->installEventFilter(this);
-	connect(ui->commandList, SIGNAL(currentItemChanged(QTreeWidgetItem*, QTreeWidgetItem*)), this, SLOT(commandChanged(QTreeWidgetItem*)));
-	connect(ui->mouseTree, SIGNAL(currentItemChanged(QTreeWidgetItem*, QTreeWidgetItem*)), this, SLOT(MouseTreeItemChanged(QTreeWidgetItem*)));
-	connect(ui->HighContrastButton, SIGNAL(clicked()), this, SLOT(AutomateEdgeColor()));
-	connect(ui->AutomateEdgeColorButton, SIGNAL(clicked()), this, SLOT(AutomateEdgeColor()));
+	connect(ui->commandList, &QTreeWidget::currentItemChanged, this, &lcQPreferencesDialog::commandChanged);
+	connect(ui->mouseTree, &QTreeWidget::currentItemChanged, this, &lcQPreferencesDialog::MouseTreeItemChanged);
+	connect(ui->HighContrastButton, &QToolButton::clicked, this, &lcQPreferencesDialog::AutomateEdgeColor);
+	connect(ui->AutomateEdgeColorButton, &QToolButton::clicked, this, &lcQPreferencesDialog::AutomateEdgeColor);
 
 	ui->partsLibrary->setText(mOptions->LibraryPath);
 	ui->ColorConfigEdit->setText(mOptions->ColorConfigPath);
diff --git a/qt/lc_qselectdialog.cpp b/qt/lc_qselectdialog.cpp
index 39058bcf..63d9dd57 100644
--- a/qt/lc_qselectdialog.cpp
+++ b/qt/lc_qselectdialog.cpp
@@ -16,7 +16,7 @@ lcQSelectDialog::lcQSelectDialog(QWidget* Parent, lcModel* Model)
 	AddChildren(ui->treeWidget->invisibleRootItem(), nullptr, Model);
 	ui->treeWidget->expandAll();
 
-	connect(ui->treeWidget, SIGNAL(itemChanged(QTreeWidgetItem*, int)), this, SLOT(itemChanged(QTreeWidgetItem*, int)));
+	connect(ui->treeWidget, &QTreeWidget::itemChanged, this, &lcQSelectDialog::itemChanged);
 }
 
 lcQSelectDialog::~lcQSelectDialog()
diff --git a/qt/lc_qutils.cpp b/qt/lc_qutils.cpp
index db6a0c0c..cd98ff80 100644
--- a/qt/lc_qutils.cpp
+++ b/qt/lc_qutils.cpp
@@ -143,7 +143,7 @@ lcQTreeWidgetColumnStretcher::lcQTreeWidgetColumnStretcher(QTreeWidget *treeWidg
 	: QObject(treeWidget->header()), m_columnToStretch(columnToStretch), m_interactiveResize(false), m_stretchWidth(0)
 {
 	parent()->installEventFilter(this);
-	connect(treeWidget->header(), SIGNAL(sectionResized(int, int, int)), SLOT(sectionResized(int, int, int)));
+	connect(treeWidget->header(), &QHeaderView::sectionResized, &lcQTreeWidgetColumnStretcher::sectionResized);
 	QHideEvent fake;
 	lcQTreeWidgetColumnStretcher::eventFilter(parent(), &fake);
 }
diff --git a/qt/lc_setsdatabasedialog.cpp b/qt/lc_setsdatabasedialog.cpp
index d2264d68..196b7197 100644
--- a/qt/lc_setsdatabasedialog.cpp
+++ b/qt/lc_setsdatabasedialog.cpp
@@ -12,9 +12,9 @@ lcSetsDatabaseDialog::lcSetsDatabaseDialog(QWidget* Parent)
 
 	mHttpManager = new lcHttpManager(this);
 
-	connect(ui->SetsTree, SIGNAL(itemDoubleClicked(QTreeWidgetItem*, int)), this, SLOT(accept()));
-	connect(this, SIGNAL(finished(int)), this, SLOT(Finished(int)));
-	connect(mHttpManager, SIGNAL(DownloadFinished(lcHttpReply*)), this, SLOT(DownloadFinished(lcHttpReply*)));
+	connect(ui->SetsTree, &QTreeWidget::itemDoubleClicked, this, &lcSetsDatabaseDialog::accept);
+	connect(this, &QDialog::finished, this, &lcSetsDatabaseDialog::Finished);
+	connect(mHttpManager, &lcHttpManager::DownloadFinished, this, &lcSetsDatabaseDialog::DownloadFinished);
 
 	mKeyListReply = mHttpManager->DownloadFile(QLatin1String("https://www.leocad.org/rebrickable.json"));
 }