diff --git a/src/backend/core/column/Column.cpp b/src/backend/core/column/Column.cpp
--- a/src/backend/core/column/Column.cpp
+++ b/src/backend/core/column/Column.cpp
@@ -783,7 +783,7 @@
 		m_content = content;
 	};
 	void run() override {
-		QByteArray bytes = QByteArray::fromBase64(m_content.toAscii());
+		QByteArray bytes = QByteArray::fromBase64(m_content.toLatin1());
 		if (m_private->columnMode() == AbstractColumn::Numeric) {
 			QVector<double>* data = new QVector<double>(bytes.size()/(int)sizeof(double));
 			memcpy(data->data(), bytes.data(), bytes.size());
diff --git a/src/backend/core/datatypes/Double2StringFilter.cpp b/src/backend/core/datatypes/Double2StringFilter.cpp
--- a/src/backend/core/datatypes/Double2StringFilter.cpp
+++ b/src/backend/core/datatypes/Double2StringFilter.cpp
@@ -77,7 +77,7 @@
 		if ( (format_str.size() != 1) || !ok ) {
 			reader->raiseError(i18n("missing or invalid format attribute"));
 		} else {
-			setNumericFormat( format_str.at(0).toAscii() );
+			setNumericFormat( format_str.at(0).toLatin1() );
 			setNumDigits( digits );
 		}
 	} else
diff --git a/src/backend/datasources/filters/JsonFilter.cpp b/src/backend/datasources/filters/JsonFilter.cpp
--- a/src/backend/datasources/filters/JsonFilter.cpp
+++ b/src/backend/datasources/filters/JsonFilter.cpp
@@ -108,7 +108,7 @@
 	for (int i = 0; i <= 100; ++i)	// me.keyCount() does not work because we have holes in enum
 		if (me.valueToKey(i))
 			list << me.valueToKey(i);
-		return list;
+	return list;
 }
 
 /*!
diff --git a/src/backend/datasources/projects/OriginProjectParser.cpp b/src/backend/datasources/projects/OriginProjectParser.cpp
--- a/src/backend/datasources/projects/OriginProjectParser.cpp
+++ b/src/backend/datasources/projects/OriginProjectParser.cpp
@@ -1234,7 +1234,7 @@
 			for (const auto& originCurve: layer.curves) {
 
 				QString data(originCurve.dataName.c_str());
-				switch(data[0].toAscii()) {
+				switch(data[0].toLatin1()) {
 				case 'T':
 				case 'E': {
 					if (originCurve.type == Origin::GraphCurve::Line || originCurve.type == Origin::GraphCurve::Scatter || originCurve.type == Origin::GraphCurve::LineSymbol
diff --git a/src/backend/lib/SignallingUndoCommand.cpp b/src/backend/lib/SignallingUndoCommand.cpp
--- a/src/backend/lib/SignallingUndoCommand.cpp
+++ b/src/backend/lib/SignallingUndoCommand.cpp
@@ -98,7 +98,7 @@
 	for (int i=0; i<m_argument_count; i++) {
 		m_argument_types[i] = QMetaType::type(type_names[i]);
 		if (m_argument_types[i]) // type is known to QMetaType
-			m_argument_data[i] = QMetaType::construct(m_argument_types[i], argument_data[i]);
+			m_argument_data[i] = QMetaType::create(m_argument_types[i], argument_data[i]);
 		else
 			qWarning("SignallingUndoCommand: failed to copy unknown type %s"
 					" (needs to be registered with qRegisterMetaType())!\n", type_names[i]);
diff --git a/src/backend/matrix/Matrix.cpp b/src/backend/matrix/Matrix.cpp
--- a/src/backend/matrix/Matrix.cpp
+++ b/src/backend/matrix/Matrix.cpp
@@ -1140,14 +1140,14 @@
 		} else if (!preview && reader->name() == "row_heights") {
 			reader->readNext();
 			QString content = reader->text().toString().trimmed();
-			QByteArray bytes = QByteArray::fromBase64(content.toAscii());
+			QByteArray bytes = QByteArray::fromBase64(content.toLatin1());
 			int count = bytes.size()/sizeof(int);
 			d->rowHeights.resize(count);
 			memcpy(d->rowHeights.data(), bytes.data(), count*sizeof(int));
 		} else if (!preview && reader->name() == "column_widths") {
 			reader->readNext();
 			QString content = reader->text().toString().trimmed();
-			QByteArray bytes = QByteArray::fromBase64(content.toAscii());
+			QByteArray bytes = QByteArray::fromBase64(content.toLatin1());
 			int count = bytes.size()/sizeof(int);
 			d->columnWidths.resize(count);
 			memcpy(d->columnWidths.data(), bytes.data(), count*sizeof(int));
@@ -1155,7 +1155,7 @@
 			//TODO: parallelize reading of columns?
 			reader->readNext();
 			QString content = reader->text().toString().trimmed();
-			QByteArray bytes = QByteArray::fromBase64(content.toAscii());
+			QByteArray bytes = QByteArray::fromBase64(content.toLatin1());
 
 			switch (d->mode) {
 			case AbstractColumn::Numeric: {
diff --git a/src/backend/worksheet/TextLabel.cpp b/src/backend/worksheet/TextLabel.cpp
--- a/src/backend/worksheet/TextLabel.cpp
+++ b/src/backend/worksheet/TextLabel.cpp
@@ -806,7 +806,7 @@
 		} else if (!preview && reader->name() == "teXImage") {
 			reader->readNext();
 			QString content = reader->text().toString().trimmed();
-			QByteArray ba = QByteArray::fromBase64(content.toAscii());
+			QByteArray ba = QByteArray::fromBase64(content.toLatin1());
 			teXImageFound = d->teXImage.loadFromData(ba);
 		} else { // unknown element
 			reader->raiseWarning(i18n("unknown element '%1'", reader->name().toString()));
diff --git a/src/commonfrontend/matrix/MatrixView.cpp b/src/commonfrontend/matrix/MatrixView.cpp
--- a/src/commonfrontend/matrix/MatrixView.cpp
+++ b/src/commonfrontend/matrix/MatrixView.cpp
@@ -112,12 +112,12 @@
 
 	//horizontal header
 	QHeaderView* h_header = m_tableView->horizontalHeader();
-	h_header->setMovable(false);
+	h_header->setSectionsMovable(false);
 	h_header->installEventFilter(this);
 
 	//vertical header
 	QHeaderView* v_header = m_tableView->verticalHeader();
-	v_header->setMovable(false);
+	v_header->setSectionsMovable(false);
 	v_header->installEventFilter(this);
 
 	//set the header sizes to the (potentially user customized) sizes stored in Matrix
@@ -544,11 +544,11 @@
 void MatrixView::goToCell() {
 	bool ok;
 
-	int col = QInputDialog::getInteger(0, i18n("Go to Cell"), i18n("Enter column"),
+	int col = QInputDialog::getInt(0, i18n("Go to Cell"), i18n("Enter column"),
 	                                   1, 1, m_matrix->columnCount(), 1, &ok);
 	if (!ok) return;
 
-	int row = QInputDialog::getInteger(0, i18n("Go to Cell"), i18n("Enter row"),
+	int row = QInputDialog::getInt(0, i18n("Go to Cell"), i18n("Enter row"),
 	                                   1, 1, m_matrix->rowCount(), 1, &ok);
 	if (!ok) return;
 
diff --git a/src/commonfrontend/spreadsheet/SpreadsheetView.cpp b/src/commonfrontend/spreadsheet/SpreadsheetView.cpp
--- a/src/commonfrontend/spreadsheet/SpreadsheetView.cpp
+++ b/src/commonfrontend/spreadsheet/SpreadsheetView.cpp
@@ -132,10 +132,10 @@
 
 	//horizontal header
 	m_horizontalHeader = new SpreadsheetHeaderView(this);
-	m_horizontalHeader->setClickable(true);
+	m_horizontalHeader->setSectionsClickable(true);
 	m_horizontalHeader->setHighlightSections(true);
 	m_tableView->setHorizontalHeader(m_horizontalHeader);
-	m_horizontalHeader->setMovable(true);
+	m_horizontalHeader->setSectionsMovable(true);
 	m_horizontalHeader->installEventFilter(this);
 
 	resizeHeader();
@@ -147,8 +147,8 @@
 
 	// vertical header
 	QHeaderView* v_header = m_tableView->verticalHeader();
-	v_header->setResizeMode(QHeaderView::Fixed);
-	v_header->setMovable(false);
+	v_header->setSectionResizeMode(QHeaderView::Fixed);
+	v_header->setSectionsMovable(false);
 	v_header->installEventFilter(this);
 
 	setFocusPolicy(Qt::StrongFocus);
@@ -1978,11 +1978,11 @@
 void SpreadsheetView::goToCell() {
 	bool ok;
 
-	int col = QInputDialog::getInteger(0, i18n("Go to Cell"), i18n("Enter column"),
+	int col = QInputDialog::getInt(0, i18n("Go to Cell"), i18n("Enter column"),
 	                                   1, 1, m_spreadsheet->columnCount(), 1, &ok);
 	if (!ok) return;
 
-	int row = QInputDialog::getInteger(0, i18n("Go to Cell"), i18n("Enter row"),
+	int row = QInputDialog::getInt(0, i18n("Go to Cell"), i18n("Enter row"),
 	                                   1, 1, m_spreadsheet->rowCount(), 1, &ok);
 	if (!ok) return;