diff --git a/src/Gui/PropertyPage.cpp b/src/Gui/PropertyPage.cpp
index 303b730516..abb87001a0 100644
--- a/src/Gui/PropertyPage.cpp
+++ b/src/Gui/PropertyPage.cpp
@@ -22,6 +22,9 @@
 
 
 #include "PreCompiled.h"
+#ifndef _PreComp_
+# include <QVBoxLayout>
+#endif
 
 #include "PropertyPage.h"
 #include "PrefWidgets.h"
diff --git a/src/Gui/WidgetFactory.cpp b/src/Gui/WidgetFactory.cpp
index 241c35f655..5ca34a3aa5 100644
--- a/src/Gui/WidgetFactory.cpp
+++ b/src/Gui/WidgetFactory.cpp
@@ -25,6 +25,8 @@
 #ifndef _PreComp_
 # include <algorithm>
 # include <limits>
+# include <QApplication>
+# include <QVBoxLayout>
 #endif
 
 #ifdef FC_OS_WIN32
diff --git a/src/Gui/Widgets.cpp b/src/Gui/Widgets.cpp
index cf59f11167..b893ef6479 100644
--- a/src/Gui/Widgets.cpp
+++ b/src/Gui/Widgets.cpp
@@ -56,6 +56,7 @@
 #include "DlgExpressionInput.h"
 #include "QuantitySpinBox_p.h"
 #include "Tools.h"
+#include "ui_DlgTreeWidget.h"
 
 using namespace Gui;
 using namespace App;
@@ -526,8 +527,9 @@ void ClearLineEdit::updateClearButton(const QString& text)
  */
 CheckListDialog::CheckListDialog( QWidget* parent, Qt::WindowFlags fl )
     : QDialog( parent, fl )
+    , ui(new Ui_DlgTreeWidget)
 {
-    ui.setupUi(this);
+    ui->setupUi(this);
 }
 
 /**
@@ -544,7 +546,7 @@ CheckListDialog::~CheckListDialog()
 void CheckListDialog::setCheckableItems( const QStringList& items )
 {
     for ( QStringList::ConstIterator it = items.begin(); it != items.end(); ++it ) {
-        QTreeWidgetItem* item = new QTreeWidgetItem(ui.treeWidget);
+        QTreeWidgetItem* item = new QTreeWidgetItem(ui->treeWidget);
         item->setText(0, *it);
         item->setCheckState(0, Qt::Unchecked);
     }
@@ -557,7 +559,7 @@ void CheckListDialog::setCheckableItems( const QStringList& items )
 void CheckListDialog::setCheckableItems( const QList<CheckListItem>& items )
 {
     for ( QList<CheckListItem>::ConstIterator it = items.begin(); it != items.end(); ++it ) {
-        QTreeWidgetItem* item = new QTreeWidgetItem(ui.treeWidget);
+        QTreeWidgetItem* item = new QTreeWidgetItem(ui->treeWidget);
         item->setText(0, (*it).first);
         item->setCheckState(0, ( (*it).second ? Qt::Checked : Qt::Unchecked));
     }
@@ -576,7 +578,7 @@ QStringList CheckListDialog::getCheckedItems() const
  */
 void CheckListDialog::accept ()
 {
-    QTreeWidgetItemIterator it(ui.treeWidget, QTreeWidgetItemIterator::Checked);
+    QTreeWidgetItemIterator it(ui->treeWidget, QTreeWidgetItemIterator::Checked);
     while (*it) {
         checked.push_back((*it)->text(0));
         ++it;
diff --git a/src/Gui/Widgets.h b/src/Gui/Widgets.h
index c4064eb50e..796a55404e 100644
--- a/src/Gui/Widgets.h
+++ b/src/Gui/Widgets.h
@@ -24,7 +24,7 @@
 #ifndef GUI_WIDGETS_H
 #define GUI_WIDGETS_H
 
-#include <Gui/ui_DlgTreeWidget.h>
+#include <QDialog>
 #include <QListWidget>
 #include <QLabel>
 #include <QLineEdit>
@@ -36,7 +36,16 @@
 #include <QToolButton>
 #include <QModelIndex>
 #include "ExpressionBinding.h"
-#include "Base/Parameter.h"
+#include <Base/Parameter.h>
+#include <memory>
+#include <FCGlobal.h>
+
+
+class QGridLayout;
+class QVBoxLayout;
+class QTreeWidget;
+class QTreeWidgetItem;
+class QSpacerItem;
 
 namespace Gui {
 class PrefCheckBox;
@@ -164,6 +173,7 @@ private:
 // ------------------------------------------------------------------------------
 
 typedef QPair<QString, bool> CheckListItem;
+class Ui_DlgTreeWidget;
 
 /**
  * The CheckListDialog class provides a dialog with a QListView with
@@ -187,7 +197,7 @@ public:
 
 private:
   QStringList checked;
-  Ui_DlgTreeWidget ui;
+  std::unique_ptr<Ui_DlgTreeWidget> ui;
 };
 
 // ------------------------------------------------------------------------------
diff --git a/src/Mod/Inspection/Gui/ViewProviderInspection.cpp b/src/Mod/Inspection/Gui/ViewProviderInspection.cpp
index f04cc0c6fe..a5099038ca 100644
--- a/src/Mod/Inspection/Gui/ViewProviderInspection.cpp
+++ b/src/Mod/Inspection/Gui/ViewProviderInspection.cpp
@@ -24,6 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
+# include <QApplication>
 # include <QMenu>
 # include <QMessageBox>
 #endif
diff --git a/src/Mod/TechDraw/Gui/QGIViewAnnotation.cpp b/src/Mod/TechDraw/Gui/QGIViewAnnotation.cpp
index 5a252d0b54..d8e3c6571c 100644
--- a/src/Mod/TechDraw/Gui/QGIViewAnnotation.cpp
+++ b/src/Mod/TechDraw/Gui/QGIViewAnnotation.cpp
@@ -24,6 +24,7 @@
 #include "PreCompiled.h"
 #ifndef _PreComp_
 #include <cmath>
+#include <QDialogButtonBox>
 #include <QGraphicsScene>
 #include <QMouseEvent>
 #include <QGraphicsSceneHoverEvent>
@@ -34,6 +35,7 @@
 #include <QPainter>
 #include <QString>
 #include <QTextOption>
+#include <QVBoxLayout>
 #include <sstream>
 #endif