diff --git a/src/common/KReportDesign_p.h b/src/common/KReportDesign_p.h
--- a/src/common/KReportDesign_p.h
+++ b/src/common/KReportDesign_p.h
@@ -22,6 +22,7 @@
 
 #include "KReportDesign.h"
 #include "KReportUnit.h"
+#include "KReportUtils_p.h"
 
 #include <QPageSize>
 #include <QPageLayout>
@@ -90,7 +91,7 @@
     KReportUnit pageUnit;
     // END OF: Visual settings only
     QString title;
-    QPageLayout pageLayout;
+    KReportPrivate::PageLayout pageLayout;
     QVarLengthArray<KReportSection*, KReportSection::Detail> sections;
 #ifdef KREPORT_SCRIPTING
     QString script;
@@ -114,7 +115,7 @@
 
     QString sectionTypeName(KReportSection::Type sectionType);
 
-    QPageLayout defaultPageLayout;
+    KReportPrivate::PageLayout defaultPageLayout;
     qreal defaultSectionHeight;
     QColor defaultSectionBackgroundColor;
 
diff --git a/src/common/KReportDocument.cpp b/src/common/KReportDocument.cpp
--- a/src/common/KReportDocument.cpp
+++ b/src/common/KReportDocument.cpp
@@ -38,7 +38,7 @@
     QString interpreter;
 #endif
     bool externalData;
-    QPageLayout page;
+    KReportPrivate::PageLayout page;
     QString pageSize;
     QString labelType;
 };
diff --git a/src/common/KReportRenderObjects.cpp b/src/common/KReportRenderObjects.cpp
--- a/src/common/KReportRenderObjects.cpp
+++ b/src/common/KReportRenderObjects.cpp
@@ -16,6 +16,7 @@
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "KReportRenderObjects.h"
+#include "KReportUtils_p.h"
 
 #include "kreport_debug.h"
 
@@ -37,7 +38,7 @@
     QString title;
     QList<OROPage*> pages;
     QList<OROSection*> sections;
-    QPageLayout pageLayout;
+    KReportPrivate::PageLayout pageLayout; 
 };
 
 ORODocument::Private::Private()
diff --git a/src/common/KReportUtils_p.h b/src/common/KReportUtils_p.h
--- a/src/common/KReportUtils_p.h
+++ b/src/common/KReportUtils_p.h
@@ -33,6 +33,7 @@
 #include <QStandardPaths>
 #include <QDebug>
 #include <QGlobalStatic>
+#include <QPageLayout>
 
 #ifdef Q_WS_X11
 #include <QX11Info>
@@ -168,6 +169,17 @@
 
 int dpiY();
 
+//! This class is wrapper that fixes a critical QTBUG-47551 bug in default constructor of QPageLayout
+//! Default constructor of QPageLayout does not initialize units.
+//! https://bugreports.qt.io/browse/QTBUG-47551
+//! @todo remove this class and go back to QPageLayout when the faulty QPageLayout implementations are no longer on the wild. That's probably for Qt 6.
+class PageLayout: public QPageLayout {
+public:
+        PageLayout();
+        PageLayout(const QPageLayout& pageLayout);
+        PageLayout& operator=(const QPageLayout& other);
+};
+
 } // KReportPrivate
 
 #endif
diff --git a/src/common/KReportUtils_p.cpp b/src/common/KReportUtils_p.cpp
--- a/src/common/KReportUtils_p.cpp
+++ b/src/common/KReportUtils_p.cpp
@@ -310,4 +310,18 @@
     return s_instance->m_dpiY;
 }
 
+PageLayout::PageLayout() : QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF(0,0,0,0))
+{
+}
+
+PageLayout::PageLayout(const QPageLayout& pageLayout) : QPageLayout(pageLayout)
+{
+}
+
+KReportPrivate::PageLayout & PageLayout::operator=(const QPageLayout& other)
+{
+    QPageLayout::operator=(other);
+    return *this;
+}
+
 }
diff --git a/src/wrtembed/KReportDesigner.cpp b/src/wrtembed/KReportDesigner.cpp
--- a/src/wrtembed/KReportDesigner.cpp
+++ b/src/wrtembed/KReportDesigner.cpp
@@ -844,9 +844,8 @@
 
 int KReportDesigner::pageWidthPx() const
 {
-    QPageLayout layout;
-    layout.setPageSize(QPageSize(KReportPageSize::pageSize(d->set->property("page-size").value().toString())));
-    layout.setOrientation(d->set->property("print-orientation").value().toString() == QLatin1String("portrait") ? QPageLayout::Portrait : QPageLayout::Landscape);
+    QPageLayout layout = QPageLayout(QPageSize(KReportPageSize::pageSize(d->set->property("page-size").value().toString())), d->set->property("print-orientation").value().toString() == QLatin1String("portrait") ? QPageLayout::Portrait : QPageLayout::Landscape, QMarginsF(0,0,0,0));;
+
     QSize pageSizePx = layout.fullRectPixels(KReportPrivate::dpiX()).size();
 
     int width = pageSizePx.width();