diff --git a/.gitignore b/.gitignore
index 3be43cf..7ca0e1c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -40,3 +40,6 @@ lib/*
 *.idb
 *.ncb
 *.suo
+
+*.cppcheck
+/*-cppcheck-build-dir
diff --git a/README.md b/README.md
index 8fe0778..660f870 100644
--- a/README.md
+++ b/README.md
@@ -24,13 +24,15 @@ Microsoft Office and can be used in any platform that **Qt 5.2** or newer suppor
 
 * Put the source code in any directory you like
 
-* Run following command at the toplevel directory of the project
+* Run following command at the toplevel directory of the project:
+
+|                    | Windows Qt MINGW           | Windows Qt MSVC     |
+|--------------------|----------------------------|---------------------|
+| ```qmake```        | ```qmake```                | ```qmake```         |
+| ```make```         | ```mingw32-make```         | ```nmake```         |
+|                    | ```mingw32-make check```   | ```nmake check```   |
+| ```make install``` | ```mingw32-make install``` | ```nmake install``` |
 
-```
-    qmake
-    make
-    make install
-```
 
 The library, the header files, and others will be installed to your system.
 
diff --git a/examples/officeopenxml/opc_package_viewer/binedit.cpp b/examples/officeopenxml/opc_package_viewer/binedit.cpp
index d02312f..4ec4b2e 100644
--- a/examples/officeopenxml/opc_package_viewer/binedit.cpp
+++ b/examples/officeopenxml/opc_package_viewer/binedit.cpp
@@ -89,7 +89,7 @@ BinEdit::BinEdit(QWidget *parent)
     m_addressBytes = 4;
     init();
     m_unmodifiedState = 0;
-    m_readOnly = false;
+    m_readOnly = 0;
     m_hexCursor = true;
     m_cursorPosition = 0;
     m_anchorPosition = 0;
@@ -130,19 +130,41 @@ void BinEdit::init()
     m_descent = fm.descent();
     m_ascent = fm.ascent();
     m_lineHeight = fm.lineSpacing();
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+    m_charWidth = fm.horizontalAdvance(QChar(QLatin1Char('M')));
+    m_margin = m_charWidth;
+    m_columnWidth = 2 * m_charWidth + fm.horizontalAdvance(QChar(QLatin1Char(' ')));
+#else
     m_charWidth = fm.width(QChar(QLatin1Char('M')));
     m_margin = m_charWidth;
     m_columnWidth = 2 * m_charWidth + fm.width(QChar(QLatin1Char(' ')));
+#endif
+
     m_numLines = m_size / m_bytesPerLine + 1;
     m_numVisibleLines = viewport()->height() / m_lineHeight;
     m_textWidth = m_bytesPerLine * m_charWidth + m_charWidth;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+    int m_numberWidth = fm.horizontalAdvance(QChar(QLatin1Char('9')));
+#else
     int m_numberWidth = fm.width(QChar(QLatin1Char('9')));
+#endif
     m_labelWidth =
         2*m_addressBytes * m_numberWidth + (m_addressBytes - 1)/2 * m_charWidth;
 
     int expectedCharWidth = m_columnWidth / 3;
     const char *hex = "0123456789abcdef";
     m_isMonospacedFont = true;
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+    while (*hex) {
+        if (fm.horizontalAdvance(QLatin1Char(*hex)) != expectedCharWidth) {
+            m_isMonospacedFont = false;
+            break;
+        }
+        ++hex;
+    }
+#else
     while (*hex) {
         if (fm.width(QLatin1Char(*hex)) != expectedCharWidth) {
             m_isMonospacedFont = false;
@@ -150,7 +172,21 @@ void BinEdit::init()
         }
         ++hex;
     }
+#endif
+
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+    if (m_isMonospacedFont && fm.horizontalAdvance(QLatin1String("M M ")) != m_charWidth * 4) {
+        // On Qt/Mac, monospace font widths may have a fractional component
+        // This breaks the assumption that width("MMM") == width('M') * 3
 
+        m_isMonospacedFont = false;
+        m_columnWidth = fm.horizontalAdvance(QLatin1String("MMM"));
+        m_labelWidth = m_addressBytes == 4
+            ? fm.horizontalAdvance(QLatin1String("MMMM:MMMM"))
+            : fm.horizontalAdvance(QLatin1String("MMMM:MMMM:MMMM:MMMM"));
+    }
+#else
     if (m_isMonospacedFont && fm.width(QLatin1String("M M ")) != m_charWidth * 4) {
         // On Qt/Mac, monospace font widths may have a fractional component
         // This breaks the assumption that width("MMM") == width('M') * 3
@@ -161,6 +197,7 @@ void BinEdit::init()
             ? fm.width(QLatin1String("MMMM:MMMM"))
             : fm.width(QLatin1String("MMMM:MMMM:MMMM:MMMM"));
     }
+#endif
 
     horizontalScrollBar()->setRange(0, 2 * m_margin + m_bytesPerLine * m_columnWidth
                                     + m_labelWidth + m_textWidth - viewport()->width());
@@ -461,7 +498,11 @@ void BinEdit::changeEvent(QEvent *e)
 void BinEdit::wheelEvent(QWheelEvent *e)
 {
     if (e->modifiers() & Qt::ControlModifier) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+        const int delta = e->pixelDelta().y();
+#else
         const int delta = e->delta();
+#endif
         if (delta < 0)
             zoomOut();
         else if (delta > 0)
@@ -505,8 +546,12 @@ int BinEdit::posAt(const QPoint &pos) const
                 break;
             QChar qc(QLatin1Char(dataAt(dataPos)));
             if (!qc.isPrint())
-                qc = 0xB7;
+                qc = QChar(0xB7);
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+            x -= fontMetrics().horizontalAdvance(qc);
+#else
             x -= fontMetrics().width(qc);
+#endif
             if (x <= 0)
                 break;
         }
@@ -787,7 +832,7 @@ void BinEdit::paintEvent(QPaintEvent *e)
                     break;
                 QChar qc(QLatin1Char(dataAt(pos, isOld)));
                 if (qc.unicode() >= 127 || !qc.isPrint())
-                    qc = 0xB7;
+                    qc = QChar(0xB7);
                 printable += qc;
             }
         } else {
@@ -830,20 +875,36 @@ void BinEdit::paintEvent(QPaintEvent *e)
 
                 if (color.isValid()) {
                     painter.fillRect(item_x - m_charWidth/2, y-m_ascent, m_columnWidth, m_lineHeight, color);
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+                    int printable_item_x = -xoffset + m_margin + m_labelWidth + m_bytesPerLine * m_columnWidth + m_charWidth
+                                           + fm.horizontalAdvance(printable.left(c));
+                    painter.fillRect(printable_item_x, y-m_ascent,
+                                     fm.horizontalAdvance(printable.at(c)),
+                                     m_lineHeight, color);
+#else
                     int printable_item_x = -xoffset + m_margin + m_labelWidth + m_bytesPerLine * m_columnWidth + m_charWidth
                                            + fm.width(printable.left(c));
                     painter.fillRect(printable_item_x, y-m_ascent,
                                      fm.width(printable.at(c)),
                                      m_lineHeight, color);
+#endif
                 }
 
                 if (!isFullySelected && pos >= selStart && pos <= selEnd) {
                     selectionRect |= QRect(item_x - m_charWidth/2, y-m_ascent, m_columnWidth, m_lineHeight);
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+                    int printable_item_x = -xoffset + m_margin + m_labelWidth + m_bytesPerLine * m_columnWidth + m_charWidth
+                                           + fm.horizontalAdvance(printable.left(c));
+                    printableSelectionRect |= QRect(printable_item_x, y-m_ascent,
+                                                    fm.horizontalAdvance(printable.at(c)),
+                                                    m_lineHeight);
+#else
                     int printable_item_x = -xoffset + m_margin + m_labelWidth + m_bytesPerLine * m_columnWidth + m_charWidth
                                            + fm.width(printable.left(c));
                     printableSelectionRect |= QRect(printable_item_x, y-m_ascent,
                                                     fm.width(printable.at(c)),
                                                     m_lineHeight);
+#endif
                 }
             }
         }
@@ -878,8 +939,13 @@ void BinEdit::paintEvent(QPaintEvent *e)
             painter.drawRect(cursorRect.adjusted(0, 0, 0, -1));
             painter.restore();
             if (m_hexCursor && m_cursorVisible) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+                if (m_lowNibble)
+                    cursorRect.adjust(fm.horizontalAdvance(itemString.left(1)), 0, 0, 0);
+#else
                 if (m_lowNibble)
                     cursorRect.adjust(fm.width(itemString.left(1)), 0, 0, 0);
+#endif
                 painter.fillRect(cursorRect, Qt::red);
                 painter.save();
                 painter.setClipRect(cursorRect);
@@ -893,8 +959,13 @@ void BinEdit::paintEvent(QPaintEvent *e)
 
         if (isFullySelected) {
                 painter.save();
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+                painter.fillRect(text_x, y-m_ascent, fm.horizontalAdvance(printable), m_lineHeight,
+                                 palette().highlight());
+#else
                 painter.fillRect(text_x, y-m_ascent, fm.width(printable), m_lineHeight,
                                  palette().highlight());
+#endif
                 painter.setPen(palette().highlightedText().color());
                 painter.drawText(text_x, y, printable);
                 painter.restore();
@@ -911,10 +982,17 @@ void BinEdit::paintEvent(QPaintEvent *e)
         }
 
         if (cursor >= 0 && !printable.isEmpty()) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+            QRect cursorRect(text_x + fm.horizontalAdvance(printable.left(cursor)),
+                             y-m_ascent,
+                             fm.horizontalAdvance(printable.at(cursor)),
+                             m_lineHeight);
+#else
             QRect cursorRect(text_x + fm.width(printable.left(cursor)),
                              y-m_ascent,
                              fm.width(printable.at(cursor)),
                              m_lineHeight);
+#endif
             painter.save();
             if (m_hexCursor || !m_cursorVisible) {
                 painter.setPen(Qt::red);
@@ -1216,7 +1294,7 @@ QString BinEdit::toolTip(const QHelpEvent *helpEvent) const
         asDouble(selStart, doubleValueOld, true);
         str << tableRowStartC << tr("<i>double</i>&nbsp;value:") << numericTableRowSepC
             << doubleValue << tableRowEndC;
-        if (doubleValue != doubleValueOld)
+        if (!qFuzzyCompare(doubleValue, doubleValueOld))
             str << tableRowStartC << tr("Previous <i>double</i>&nbsp;value:") << numericTableRowSepC
                 << doubleValueOld << tableRowEndC;
         str << "</table>";
@@ -1230,7 +1308,7 @@ QString BinEdit::toolTip(const QHelpEvent *helpEvent) const
         asFloat(selStart, floatValueOld, true);
         str << tableRowStartC << tr("<i>float</i>&nbsp;value:") << numericTableRowSepC
             << floatValue << tableRowEndC;
-        if (floatValue != floatValueOld)
+        if (!qFuzzyCompare(floatValue, floatValueOld))
             str << tableRowStartC << tr("Previous <i>float</i>&nbsp;value:") << numericTableRowSepC
                 << floatValueOld << tableRowEndC;
 
@@ -1330,7 +1408,7 @@ void BinEdit::keyPressEvent(QKeyEvent *e)
             } else {
                 if (c.unicode() >= 128 || !c.isPrint())
                     continue;
-                changeData(m_cursorPosition, c.unicode(), m_cursorPosition + 1);
+                changeData(m_cursorPosition, c.unicode(), true);
                 setCursorPosition(m_cursorPosition + 1);
             }
             setBlinkingCursorEnabled(true);
diff --git a/examples/officeopenxml/opc_package_viewer/binedit.h b/examples/officeopenxml/opc_package_viewer/binedit.h
index 1e8698f..92271e4 100644
--- a/examples/officeopenxml/opc_package_viewer/binedit.h
+++ b/examples/officeopenxml/opc_package_viewer/binedit.h
@@ -88,7 +88,7 @@ class BinEdit : public QAbstractScrollArea
     bool isReadOnly() const;
 
     int find(const QByteArray &pattern, int from = 0,
-             QTextDocument::FindFlags findFlags = 0);
+             QTextDocument::FindFlags findFlags = QTextDocument::FindFlags());
 
     void selectAll();
     void clear();
@@ -110,7 +110,7 @@ class BinEdit : public QAbstractScrollArea
 
 public Q_SLOTS:
     void highlightSearchResults(const QByteArray &pattern,
-        QTextDocument::FindFlags findFlags = 0);
+                                QTextDocument::FindFlags findFlags = QTextDocument::FindFlags());
     void copy(bool raw = false);
     void setNewWindowRequestAllowed(bool c);
 
diff --git a/examples/officeopenxml/opc_package_viewer/imagewidget.cpp b/examples/officeopenxml/opc_package_viewer/imagewidget.cpp
index b34e87b..c9e0b8f 100644
--- a/examples/officeopenxml/opc_package_viewer/imagewidget.cpp
+++ b/examples/officeopenxml/opc_package_viewer/imagewidget.cpp
@@ -64,6 +64,7 @@ ImageWidgetPrivate::ImageWidgetPrivate(ImageWidget *q) :
     m_scaleMax = 64;
     m_wheelScaleEnabled = true;
     m_autoAdjustEnabled = false;
+    m_pixmapItem = nullptr;
 }
 
 /*!
@@ -195,7 +196,7 @@ bool ImageWidget::isMouseWheelEnabled() const
 */
 void ImageWidget::setCurrentScale(double factor)
 {
-    if (factor == 0) {
+    if (qFuzzyCompare(factor, 0)) {
         if (!d->m_autoAdjustEnabled) {
             d->m_autoAdjustEnabled = true;
             d->doAutoFit();
@@ -245,8 +246,11 @@ void ImageWidget::wheelEvent(QWheelEvent *event)
     if (d->m_wheelScaleEnabled) {
         //Disable auto fit!!
         d->m_autoAdjustEnabled = false;
-
+#if (QT_VERSION >= QT_VERSION_CHECK(5,15,14))
+        double numDegrees = -event->angleDelta().y() / 8.0;
+#else
         double numDegrees = -event->delta() / 8.0;
+#endif
         double numSteps = numDegrees / 15.0;
         double factor = pow(1.125, numSteps);
 
diff --git a/examples/officeopenxml/opc_packages_diff/mainwindow.cpp b/examples/officeopenxml/opc_packages_diff/mainwindow.cpp
index d4fcfbf..82b092c 100644
--- a/examples/officeopenxml/opc_packages_diff/mainwindow.cpp
+++ b/examples/officeopenxml/opc_packages_diff/mainwindow.cpp
@@ -142,7 +142,7 @@ void MainWindow::onRunButtonClicked()
         return;
     }
 
-    QStringList args = ui->diffArgumentsEdit->text().split(QRegularExpression("\\s+"), QString::SkipEmptyParts);
+    QStringList args = ui->diffArgumentsEdit->text().split(QRegularExpression("\\s+"), Qt::SkipEmptyParts);
     for (int i=0; i<args.size(); ++i) {
         if (args[i] == QLatin1String("%1"))
             args[i] = m_dir1->path();
diff --git a/src/3rdParty/karchive/src/karchive.cpp b/src/3rdParty/karchive/src/karchive.cpp
index 1b3371b..16541a1 100644
--- a/src/3rdParty/karchive/src/karchive.cpp
+++ b/src/3rdParty/karchive/src/karchive.cpp
@@ -172,7 +172,7 @@ bool KArchive::close()
         closeSucceeded = d->saveFile->commit();
         delete d->saveFile;
         d->saveFile = 0;
-    } if (d->deviceOwned) {
+    } else if (d->deviceOwned) {
         delete d->dev; // we created it ourselves in open()
     }
 
@@ -234,9 +234,15 @@ bool KArchive::addLocalFile(const QString &fileName, const QString &destName)
         if (symLinkTarget.isEmpty()) { // Mac or Windows
             symLinkTarget = fileInfo.symLinkTarget();
         }
+        QDateTime fileWasCreated;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+        fileWasCreated = fileInfo.birthTime();
+#else
+        fileWasCreated = fileInfo.created();
+#endif
         return writeSymLink(destName, symLinkTarget, fileInfo.owner(),
                             fileInfo.group(), fi.st_mode, fileInfo.lastRead(), fileInfo.lastModified(),
-                            fileInfo.created());
+                            fileWasCreated);
     }/*end if*/
 
     qint64 size = fileInfo.size();
@@ -249,9 +255,14 @@ bool KArchive::addLocalFile(const QString &fileName, const QString &destName)
         //qWarning() << "couldn't open file " << fileName;
         return false;
     }
-
+    QDateTime fileWasCreated;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    fileWasCreated = fileInfo.birthTime();
+#else
+    fileWasCreated = fileInfo.created();
+#endif
     if (!prepareWriting(destName, fileInfo.owner(), fileInfo.group(), size,
-                        fi.st_mode, fileInfo.lastRead(), fileInfo.lastModified(), fileInfo.created())) {
+                        fi.st_mode, fileInfo.lastRead(), fileInfo.lastModified(), fileWasCreated)) {
         //qWarning() << " prepareWriting" << destName << "failed";
         return false;
     }
@@ -316,9 +327,11 @@ bool KArchive::writeFile(const QString &name, const QByteArray &data,
 
     // Write data
     // Note: if data is null, don't call write, it would terminate the KCompressionDevice
-    if (data.constData() && size && !writeData(data.constData(), size)) {
-        //qWarning() << "writeData failed";
-        return false;
+    if (!data.isNull() && !data.isEmpty()) {
+        if (!writeData(data.constData(), size)) {
+            //qWarning() << "writeData failed";
+            return false;
+        }
     }
 
     if (!finishWriting(size)) {
@@ -515,7 +528,13 @@ QDateTime KArchivePrivate::time_tToDateTime(uint time_t)
     if (time_t == uint(-1)) {
         return QDateTime();
     }
-    return QDateTime::fromTime_t(time_t);
+    QDateTime retVal;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    retVal = QDateTime::fromSecsSinceEpoch(time_t);
+#else
+    retVal = QDateTime::fromTime_t(time_t);
+#endif
+    return retVal;
 }
 
 ////////////////////////////////////////////////////////////////////////
@@ -874,9 +893,11 @@ bool KArchiveDirectory::copyTo(const QString &dest, bool recursiveCopy) const
             }
         }
     } while (!dirStack.isEmpty());
-
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    std::sort(fileList.begin(), fileList.end(), sortByPosition);    // sort on d->pos, so we have a linear access
+#else
     qSort(fileList.begin(), fileList.end(), sortByPosition);    // sort on d->pos, so we have a linear access
-
+#endif
     for (QList<const KArchiveFile *>::const_iterator it = fileList.constBegin(), end = fileList.constEnd();
             it != end; ++it) {
         const KArchiveFile *f = *it;
diff --git a/src/3rdParty/karchive/src/karchiveentry.h b/src/3rdParty/karchive/src/karchiveentry.h
index aad6840..a827d61 100644
--- a/src/3rdParty/karchive/src/karchiveentry.h
+++ b/src/3rdParty/karchive/src/karchiveentry.h
@@ -25,6 +25,7 @@
 #include <sys/types.h>
 
 #include <karchive_export.h>
+#include <QDateTime>
 
 #ifdef Q_OS_WIN
 #include <qplatformdefs.h> // mode_t
diff --git a/src/3rdParty/karchive/src/kcompressiondevice.cpp b/src/3rdParty/karchive/src/kcompressiondevice.cpp
index 4f7bba0..fa9e938 100644
--- a/src/3rdParty/karchive/src/kcompressiondevice.cpp
+++ b/src/3rdParty/karchive/src/kcompressiondevice.cpp
@@ -45,7 +45,7 @@ class KCompressionDevice::Private
     Private() : bNeedHeader(true), bSkipHeaders(false),
         bOpenedUnderlyingDevice(false),
         bIgnoreData(false),
-        type(KCompressionDevice::None) {}
+        result(KFilterBase::Result()), filter(nullptr), type(KCompressionDevice::None)  {}
     bool bNeedHeader;
     bool bSkipHeaders;
     bool bOpenedUnderlyingDevice;
diff --git a/src/3rdParty/karchive/src/kzip.cpp b/src/3rdParty/karchive/src/kzip.cpp
index c2d0d31..6685a1f 100644
--- a/src/3rdParty/karchive/src/kzip.cpp
+++ b/src/3rdParty/karchive/src/kzip.cpp
@@ -76,7 +76,13 @@ static uint transformFromMsDos(const char *buffer)
     QDate qd(y, o, d);
 
     QDateTime dt(qd, qt);
-    return dt.toTime_t();
+    uint retVal;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    retVal = dt.toSecsSinceEpoch();
+#else
+    retVal = dt.toTime_t()
+#endif
+    return retVal;
 }
 
 // == parsing routines for zip headers
@@ -930,7 +936,11 @@ bool KZip::closeArchive()
             extfield[4] = 1 | 2 | 4;    // specify flags from local field
             // (unless I misread the spec)
             // provide only modification time
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+            unsigned long time = static_cast<unsigned long>(it.value()->date().toSecsSinceEpoch()); // Convert 64 to 32 bits!
+#else
             unsigned long time = (unsigned long)it.value()->date().toTime_t();
+#endif
             extfield[5] = char(time);
             extfield[6] = char(time >> 8);
             extfield[7] = char(time >> 16);
@@ -1032,9 +1042,15 @@ bool KZip::doPrepareWriting(const QString &name, const QString &user,
         return false;
     }
 
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    uint atime = accessTime.toSecsSinceEpoch();
+    uint mtime = modificationTime.toSecsSinceEpoch();
+    uint ctime = creationTime.toSecsSinceEpoch();
+#else
     uint atime = accessTime.toTime_t();
     uint mtime = modificationTime.toTime_t();
     uint ctime = creationTime.toTime_t();
+#endif
 
     // Find or create parent dir
     KArchiveDirectory *parentDir = rootDir();
@@ -1186,6 +1202,7 @@ bool KZip::doPrepareWriting(const QString &name, const QString &user,
 
 bool KZip::doFinishWriting(qint64 size)
 {
+    Q_ASSERT(d->m_currentFile);
     if (d->m_currentFile->encoding() == 8) {
         // Finish
         (void)d->m_currentDev->write(0, 0);
@@ -1194,7 +1211,6 @@ bool KZip::doFinishWriting(qint64 size)
     // If 0, d->m_currentDev was device() - don't delete ;)
     d->m_currentDev = 0;
 
-    Q_ASSERT(d->m_currentFile);
     //qDebug() << "fileName: " << d->m_currentFile->path();
     //qDebug() << "getpos (at): " << device()->pos();
     d->m_currentFile->setSize(size);
diff --git a/src/officeopenxml/mce/mcexmlstreamreader.cpp b/src/officeopenxml/mce/mcexmlstreamreader.cpp
index 2a84344..bd9c19a 100644
--- a/src/officeopenxml/mce/mcexmlstreamreader.cpp
+++ b/src/officeopenxml/mce/mcexmlstreamreader.cpp
@@ -25,6 +25,7 @@
 #include <QtCore/qstringlist.h>
 #include <QtCore/qregularexpression.h>
 #include <QtCore/qdebug.h>
+#include <QVectorIterator>
 
 namespace QtOfficeOpenXml {
 namespace Mce {
@@ -181,7 +182,7 @@ void MceXmlElementState::addNamespacePrefix(const QString &prefix, const QString
 }
 
 XmlStreamReaderPrivate::XmlStreamReaderPrivate(QXmlStreamReader *reader, XmlStreamReader *q):
-    mceParseFlags(0), hasFoundRootElement(false), reader(reader), q_ptr(q)
+    mceParseFlags(0), extensionElementDepth(0), hasFoundRootElement(false), reader(reader), q_ptr(q)
 {
 }
 
@@ -455,7 +456,11 @@ QXmlStreamReader::TokenType XmlStreamReader::readNext()
 
                     //Figure out whether this element's requires is satisfied.
                     bool ok = true;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+                    QStringView nsPrefixString = d->reader->attributes().value(QLatin1String("Requires"));
+#else
                     QStringRef nsPrefixString = d->reader->attributes().value(QLatin1String("Requires"));
+#endif
                     if (!nsPrefixString.isEmpty()) {
                         QStringList nsPrefixList = nsPrefixString.toString().split(QRegularExpression(QStringLiteral("[ \\t\\r\\n]+")));
                         foreach (QString nsPrefix, nsPrefixList) {
@@ -593,7 +598,11 @@ QXmlStreamReader::TokenType XmlStreamReaderPrivate::doReadNext_1()
 
             if (!nonUnderstoodNamespaces.isEmpty()) {
                 //Find out non-understood and ignorable namespaces.
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+                QStringView nsPrefixString = reader->attributes().value(QLatin1String(mcNamespace), QLatin1String("Ignorable"));
+#else
                 QStringRef nsPrefixString = reader->attributes().value(QLatin1String(mcNamespace), QLatin1String("Ignorable"));
+#endif
                 if (!nsPrefixString.isEmpty()) {
                     QStringList nsPrefixList = nsPrefixString.toString().split(QRegularExpression(QStringLiteral("[ \\t\\r\\n]+")));
                     foreach (QString nsPrefix, nsPrefixList) {
@@ -621,7 +630,11 @@ QXmlStreamReader::TokenType XmlStreamReaderPrivate::doReadNext_1()
                     break;
 
                 //Deal with ProcessContent attribute.
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+                QStringView pcAttribValue = reader->attributes().value(QLatin1String(mcNamespace), QLatin1String("ProcessContent"));
+#else
                 QStringRef pcAttribValue = reader->attributes().value(QLatin1String(mcNamespace), QLatin1String("ProcessContent"));
+#endif
                 if (!pcAttribValue.isEmpty()) {
                     QStringList pcNameList = pcAttribValue.toString().split(QRegularExpression(QStringLiteral("[ \\t\\r\\n]+")));
                     foreach (const QString pcName, pcNameList) {
@@ -802,7 +815,11 @@ bool XmlStreamReader::isStandaloneDocument() const
      version string as specified in the XML declaration.
      Otherwise an empty string is returned.
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::documentVersion() const
+#else
 QStringRef XmlStreamReader::documentVersion() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->documentVersion();
@@ -812,7 +829,11 @@ QStringRef XmlStreamReader::documentVersion() const
      encoding string as specified in the XML declaration.
      Otherwise an empty string is returned.
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::documentEncoding() const
+#else
 QStringRef XmlStreamReader::documentEncoding() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->documentEncoding();
@@ -919,7 +940,11 @@ QString XmlStreamReader::readElementText(QXmlStreamReader::ReadElementTextBehavi
 
   \sa namespaceUri(), qualifiedName()
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::name() const
+#else
 QStringRef XmlStreamReader::name() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->name();
@@ -930,7 +955,11 @@ QStringRef XmlStreamReader::name() const
 
   \sa name(), qualifiedName()
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::namespaceUri() const
+#else
 QStringRef XmlStreamReader::namespaceUri() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->namespaceUri();
@@ -939,7 +968,11 @@ QStringRef XmlStreamReader::namespaceUri() const
 /*!
   Returns the qualified name of a StartElement or EndElement;
 */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::qualifiedName() const
+#else
 QStringRef XmlStreamReader::qualifiedName() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->qualifiedName();
@@ -949,7 +982,11 @@ QStringRef XmlStreamReader::qualifiedName() const
 
 \sa name(), qualifiedName()
 */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::prefix() const
+#else
 QStringRef XmlStreamReader::prefix() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->prefix();
@@ -958,7 +995,11 @@ QStringRef XmlStreamReader::prefix() const
 /*!
   Returns the data of a ProcessingInstruction.
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::processingInstructionData() const
+#else
 QStringRef XmlStreamReader::processingInstructionData() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->processingInstructionData();
@@ -967,7 +1008,11 @@ QStringRef XmlStreamReader::processingInstructionData() const
 /*!
   Returns the target of a ProcessingInstruction.
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::processingInstructionTarget() const
+#else
 QStringRef XmlStreamReader::processingInstructionTarget() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->processingInstructionTarget();
@@ -976,7 +1021,11 @@ QStringRef XmlStreamReader::processingInstructionTarget() const
 /*!  Returns the text of Characters, Comment, DTD, or
   EntityReference.
  */
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+QStringView XmlStreamReader::text() const
+#else
 QStringRef XmlStreamReader::text() const
+#endif
 {
     Q_D(const XmlStreamReader);
     return d->reader->text();
diff --git a/src/officeopenxml/mce/mcexmlstreamreader.h b/src/officeopenxml/mce/mcexmlstreamreader.h
index 184a24f..94cba91 100644
--- a/src/officeopenxml/mce/mcexmlstreamreader.h
+++ b/src/officeopenxml/mce/mcexmlstreamreader.h
@@ -77,9 +77,13 @@ class Q_OFFICEOPENXML_EXPORT XmlStreamReader
     inline bool isProcessingInstruction() const { return tokenType() == QXmlStreamReader::ProcessingInstruction; }
 
     bool isStandaloneDocument() const;
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    QStringView documentVersion() const;
+    QStringView documentEncoding() const;
+#else
     QStringRef documentVersion() const;
     QStringRef documentEncoding() const;
-
+#endif
     qint64 lineNumber() const;
     qint64 columnNumber() const;
     qint64 characterOffset() const;
@@ -87,7 +91,15 @@ class Q_OFFICEOPENXML_EXPORT XmlStreamReader
     QXmlStreamAttributes attributes() const;
 
     QString readElementText(QXmlStreamReader::ReadElementTextBehaviour behaviour = QXmlStreamReader::ErrorOnUnexpectedElement);
-
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    QStringView name() const;
+    QStringView namespaceUri() const;
+    QStringView qualifiedName() const;
+    QStringView prefix() const;
+    QStringView processingInstructionTarget() const;
+    QStringView processingInstructionData() const;
+    QStringView text() const;
+#else
     QStringRef name() const;
     QStringRef namespaceUri() const;
     QStringRef qualifiedName() const;
@@ -95,7 +107,7 @@ class Q_OFFICEOPENXML_EXPORT XmlStreamReader
     QStringRef processingInstructionTarget() const;
     QStringRef processingInstructionData() const;
     QStringRef text() const;
-
+#endif
     QXmlStreamNamespaceDeclarations namespaceDeclarations() const;
 
     void raiseError(const QString& message = QString());
diff --git a/src/officeopenxml/mce/mcexmlstreamreader_p.h b/src/officeopenxml/mce/mcexmlstreamreader_p.h
index d1be8e9..11e2b0d 100644
--- a/src/officeopenxml/mce/mcexmlstreamreader_p.h
+++ b/src/officeopenxml/mce/mcexmlstreamreader_p.h
@@ -89,6 +89,8 @@ class MceXmlElementStateData : public QSharedData
     MceXmlElementStateData(const MceXmlElementStateData &other)
         :QSharedData(other), ignorableNamespaces(other.ignorableNamespaces)
         , processContentNeededElements(other.processContentNeededElements)
+        , extensionElements(other.extensionElements)
+        , namespacePrefixes(other.namespacePrefixes)
     {}
     ~MceXmlElementStateData(){}
 
diff --git a/src/officeopenxml/ooxml/ooxmlschames_p.h b/src/officeopenxml/ooxml/ooxmlschames_p.h
index 3eaa410..bea9ce1 100644
--- a/src/officeopenxml/ooxml/ooxmlschames_p.h
+++ b/src/officeopenxml/ooxml/ooxmlschames_p.h
@@ -44,7 +44,7 @@ namespace Ooxml {
 
 struct OoxmlSchamesData
 {
-    OoxmlSchamesData(int id, const QString transitional, const QString &strict=QString(), const QString &prefix=QString()) :
+    OoxmlSchamesData(int id, const QString &transitional, const QString &strict=QString(), const QString &prefix=QString()) :
         id(id), prefix(prefix), strict(strict), transitional(transitional)
     {}
 
diff --git a/src/officeopenxml/opc/opcpackagepart.cpp b/src/officeopenxml/opc/opcpackagepart.cpp
index 12981d9..2cda877 100644
--- a/src/officeopenxml/opc/opcpackagepart.cpp
+++ b/src/officeopenxml/opc/opcpackagepart.cpp
@@ -36,7 +36,7 @@ namespace Opc {
  * \internal
  */
 
-PackagePartPrivate::PackagePartPrivate(const QString &partName, const QString type, PackagePart *q, Package *package)
+PackagePartPrivate::PackagePartPrivate(const QString &partName, const QString &type, PackagePart *q, Package *package)
     :q_ptr(q), package(package), partName(partName), contentType(type), relationshipHelper(0)
 {
 
diff --git a/src/officeopenxml/opc/opcpackagepart_p.h b/src/officeopenxml/opc/opcpackagepart_p.h
index 69109ad..c11ed6c 100644
--- a/src/officeopenxml/opc/opcpackagepart_p.h
+++ b/src/officeopenxml/opc/opcpackagepart_p.h
@@ -46,7 +46,7 @@ class OFFICEOPENXML_AUTOTEST_EXPORT PackagePartPrivate
     Q_DECLARE_PUBLIC(PackagePart)
 
 public:
-    PackagePartPrivate(const QString &partName, const QString type, PackagePart *q, Package *package);
+    PackagePartPrivate(const QString &partName, const QString &type, PackagePart *q, Package *package);
     virtual ~PackagePartPrivate();
     void ensureRelationship() const;
     bool isRelationshipPart() const;
diff --git a/src/officeopenxml/opc/opcpartbasedpackageproperties.cpp b/src/officeopenxml/opc/opcpartbasedpackageproperties.cpp
index 9642f46..607f08f 100644
--- a/src/officeopenxml/opc/opcpartbasedpackageproperties.cpp
+++ b/src/officeopenxml/opc/opcpartbasedpackageproperties.cpp
@@ -114,7 +114,11 @@ void PartBasedPackageProperties::doLoadFromXml(QIODevice *device)
 
     while (!reader.atEnd()) {
          if (reader.readNextStartElement()) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+             const QStringView name = reader.name();
+#else
              const QStringRef name = reader.name();
+#endif
              //Todo, "keywords" support lang attribute.
              for (int idx=0; idx<16; ++idx) {
                  if (name == QLatin1String(propertiesNameTable[idx])) {
@@ -151,6 +155,7 @@ void PartBasedPackageProperties::doSaveToXml(QIODevice *device)
         switch (pe) {
         case PE_Category:
         case PE_ContentStatus:
+        case PE_ContentType:
         case PE_Keywords:
         case PE_LastModifiedBy:
         case PE_LastPrinted:
@@ -199,10 +204,18 @@ QDateTime PartBasedPackageProperties::dateTimeProperty(PropertyEnum pe) const
         dt = QDateTime::fromString(dt_string, Qt::TextDate);
     if (dt.isNull())
         dt = QDateTime::fromString(dt_string, Qt::RFC2822Date);
+#if (QT_VERSION >= QT_VERSION_CHECK(5,13,0))
+    QLocale ql;
+    if (dt.isNull())
+        dt = ql.toDateTime(dt_string, QLocale::LongFormat);
+    if (dt.isNull())
+        dt = ql.toDateTime(dt_string, QLocale::ShortFormat);
+#else
     if (dt.isNull())
         dt = QDateTime::fromString(dt_string, Qt::SystemLocaleLongDate);
     if (dt.isNull())
         dt = QDateTime::fromString(dt_string, Qt::SystemLocaleShortDate);
+#endif
     return dt;
 }
 
diff --git a/src/officeopenxml/opc/opcutils_p.h b/src/officeopenxml/opc/opcutils_p.h
index 0e79633..ca6563f 100644
--- a/src/officeopenxml/opc/opcutils_p.h
+++ b/src/officeopenxml/opc/opcutils_p.h
@@ -37,8 +37,9 @@
 
 #include <QtOfficeOpenXml/officeopenxmlglobal.h>
 
-class QString;
-class QStringList;
+#include <QString>
+#include <QStringList>
+
 
 namespace QtOfficeOpenXml {
 namespace Opc {
diff --git a/src/officeopenxml/opc/opczippackagepart.cpp b/src/officeopenxml/opc/opczippackagepart.cpp
index 4f91832..96e17c2 100644
--- a/src/officeopenxml/opc/opczippackagepart.cpp
+++ b/src/officeopenxml/opc/opczippackagepart.cpp
@@ -38,8 +38,8 @@ namespace Opc {
  * \class QtOfficeOpenXml::Opc::ZipPackagePartPrivate
  * \internal
  */
-ZipPackagePartPrivate::ZipPackagePartPrivate(const QString &partName, const QString type, PackagePart *q, Package *package)
-    :PackagePartPrivate(partName, type, q, package), zipFileEntry(0), device(0)
+ZipPackagePartPrivate::ZipPackagePartPrivate(const QString &partName, const QString &type, PackagePart *q, Package *package)
+    :PackagePartPrivate(partName, type, q, package), zipArchive(0), zipFileEntry(0), device(0)
 {
 }
 
diff --git a/src/officeopenxml/opc/opczippackagepart_p.h b/src/officeopenxml/opc/opczippackagepart_p.h
index 98ab85a..414a476 100644
--- a/src/officeopenxml/opc/opczippackagepart_p.h
+++ b/src/officeopenxml/opc/opczippackagepart_p.h
@@ -48,7 +48,7 @@ namespace Opc {
 class ZipPackagePartPrivate : public PackagePartPrivate
 {
 public:
-    ZipPackagePartPrivate(const QString &partName, const QString type, PackagePart *q, Package *package);
+    ZipPackagePartPrivate(const QString &partName, const QString &type, PackagePart *q, Package *package);
 
     KZip *zipArchive;
     const KZipFileEntry *zipFileEntry;
diff --git a/src/officeopenxml/sml/smlcell.cpp b/src/officeopenxml/sml/smlcell.cpp
index 6eb6728..a676b35 100644
--- a/src/officeopenxml/sml/smlcell.cpp
+++ b/src/officeopenxml/sml/smlcell.cpp
@@ -59,7 +59,7 @@ Cell::CellType Cell::cellType() const
     Q_D(const Cell);
     if (d->attrs_raw.contains(QStringLiteral("t"))) {
         QString t = d->attrs_raw[QStringLiteral("t")];
-        for (int i=0; i<sizeof(cellTypeNameTable)/sizeof(cellTypeNameTable[0]); ++i) {
+        for (size_t i=0; i<sizeof(cellTypeNameTable)/sizeof(cellTypeNameTable[0]); ++i) {
             if (QLatin1String(cellTypeNameTable[i]) == t)
                 return (CellType)i;
         }
diff --git a/src/officeopenxml/sml/smllargedocumentreader.cpp b/src/officeopenxml/sml/smllargedocumentreader.cpp
index b38be82..5fc861c 100644
--- a/src/officeopenxml/sml/smllargedocumentreader.cpp
+++ b/src/officeopenxml/sml/smllargedocumentreader.cpp
@@ -32,7 +32,7 @@ namespace QtOfficeOpenXml {
 namespace Sml {
 
 LargeDocumentReaderPrivate::LargeDocumentReaderPrivate(LargeDocumentReader *q) :
-    ooxmlSchameType(Ooxml::TransitionalSchame),
+    ooxmlSchameType(Ooxml::TransitionalSchame), package(0),
     q_ptr(q)
 {
 }
diff --git a/src/officeopenxml/sml/smllargedocumentwriter.cpp b/src/officeopenxml/sml/smllargedocumentwriter.cpp
index d8296bd..ef90190 100644
--- a/src/officeopenxml/sml/smllargedocumentwriter.cpp
+++ b/src/officeopenxml/sml/smllargedocumentwriter.cpp
@@ -30,7 +30,7 @@ namespace QtOfficeOpenXml {
 namespace Sml {
 
 LargeDocumentWriterPrivate::LargeDocumentWriterPrivate(LargeDocumentWriter *q) :
-    isClosed(false), ooxmlSchameType(Ooxml::TransitionalSchame),
+    isClosed(false), ooxmlSchameType(Ooxml::TransitionalSchame), package(nullptr),
     q_ptr(q)
 {
 }
diff --git a/src/officeopenxml/sml/smlworkbook.cpp b/src/officeopenxml/sml/smlworkbook.cpp
index dfa8e13..dccc415 100644
--- a/src/officeopenxml/sml/smlworkbook.cpp
+++ b/src/officeopenxml/sml/smlworkbook.cpp
@@ -37,7 +37,7 @@ QString Workbook::bookView(const QString &attribute) const
         return QString();
     if (!bookViews_raw[0].contains(attribute))
         return QString();
-    return bookViews_raw[0][attribute].toInt();
+    return QString::fromStdString(bookViews_raw[0][attribute].toStdString());
 }
 
 void Workbook::setBookView(const QString &attribute, const QString &val)