diff --git a/examples/gallery/slider/CustomSliderSkinlet.cpp b/examples/gallery/slider/CustomSliderSkinlet.cpp
index 54dd1cea..75a7f990 100644
--- a/examples/gallery/slider/CustomSliderSkinlet.cpp
+++ b/examples/gallery/slider/CustomSliderSkinlet.cpp
@@ -37,11 +37,7 @@ namespace
         TicksNode( const QColor& color )
             : m_geometry( QSGGeometry::defaultAttributes_Point2D(), 0 )
         {
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 8, 0 )
             m_geometry.setDrawingMode( QSGGeometry::DrawLines );
-#else
-            m_geometry.setDrawingMode( GL_LINES );
-#endif
             m_geometry.setVertexDataPattern( QSGGeometry::StaticPattern );
 
             m_material.setColor( color );
diff --git a/examples/iotdashboard/iotdashboard.pro b/examples/iotdashboard/iotdashboard.pro
index 1b6a87b7..1669d26d 100644
--- a/examples/iotdashboard/iotdashboard.pro
+++ b/examples/iotdashboard/iotdashboard.pro
@@ -1,6 +1,7 @@
 CONFIG += qskexample
 
 QT += svg
+QT += quick_private # TODO: examples should not use private headers
 
 SOURCES += \
     Box.cpp \
diff --git a/examples/iotdashboard/nodes/DiagramDataNode.cpp b/examples/iotdashboard/nodes/DiagramDataNode.cpp
index cd155df3..a5fa2006 100644
--- a/examples/iotdashboard/nodes/DiagramDataNode.cpp
+++ b/examples/iotdashboard/nodes/DiagramDataNode.cpp
@@ -48,11 +48,7 @@ void DiagramDataNode::update( const QRectF& rect, Type type,
     m_type = type;
 
     const auto drawingMode =
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 8, 0 )
         ( m_type == Line ) ? QSGGeometry::DrawLines : QSGGeometry::DrawTriangleStrip;
-#else
-        ( m_type == Line ) ? GL_LINES : GL_TRIANGLE_STRIP;
-#endif
 
     m_geometry.setDrawingMode( drawingMode );
 
diff --git a/examples/iotdashboard/nodes/DiagramSegmentsNode.cpp b/examples/iotdashboard/nodes/DiagramSegmentsNode.cpp
index 9ec72f56..976abae7 100644
--- a/examples/iotdashboard/nodes/DiagramSegmentsNode.cpp
+++ b/examples/iotdashboard/nodes/DiagramSegmentsNode.cpp
@@ -10,11 +10,7 @@
 DiagramSegmentsNode::DiagramSegmentsNode()
     : m_geometry( QSGGeometry::defaultAttributes_Point2D(), 0 )
 {
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 8, 0 )
     m_geometry.setDrawingMode( QSGGeometry::DrawLines );
-#else
-    m_geometry.setDrawingMode( GL_LINES );
-#endif
 
     setGeometry( &m_geometry );
     setMaterial( &m_material );
diff --git a/examples/iotdashboard/nodes/RadialTickmarksNode.cpp b/examples/iotdashboard/nodes/RadialTickmarksNode.cpp
index 13a86dbc..cb5d7449 100644
--- a/examples/iotdashboard/nodes/RadialTickmarksNode.cpp
+++ b/examples/iotdashboard/nodes/RadialTickmarksNode.cpp
@@ -24,11 +24,7 @@ class RadialTickmarksNodePrivate final : public QSGGeometryNodePrivate
     RadialTickmarksNodePrivate()
         : geometry( QSGGeometry::defaultAttributes_Point2D(), 0 )
     {
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 8, 0 )
         geometry.setDrawingMode( QSGGeometry::DrawLines );
-#else
-        geometry.setDrawingMode( GL_LINES );
-#endif
         geometry.setVertexDataPattern( QSGGeometry::StaticPattern );
     }
 
diff --git a/features/qskconfig.pri b/features/qskconfig.pri
index f25494e7..136c76b8 100644
--- a/features/qskconfig.pri
+++ b/features/qskconfig.pri
@@ -37,7 +37,7 @@ CONFIG           += no_private_qt_headers_warning
 CONFIG           += warn_on
 CONFIG           += no_keywords
 CONFIG           += silent
-CONFIG           -= depend_includepath
+#CONFIG           -= depend_includepath
 
 CONFIG           += strict_c++
 CONFIG           += c++11
@@ -64,16 +64,6 @@ RCC_DIR      = rcc
 
 QSK_CONFIG += QskDll
 
-*-g++* {
-
-    GCC_VERSION = $$system("$$QMAKE_CXX -dumpversion")
-    equals(GCC_VERSION,4) || contains(GCC_VERSION, 4.* ) {
-
-        # gcc4 is too old for certain checks
-        CONFIG -= pedantic sanitize
-    }
-}
-
 linux {
 
     pedantic {
@@ -83,14 +73,17 @@ linux {
         # Qt headers do not stand pedantic checks, so it's better
         # to exclude them by declaring them as system includes
 
+        #CONFIG += qtassysteminclude
+    }
+
+    qtassysteminclude {
+
         # As most distros set QT_INSTALL_HEADERS to /usr/include we
         # would run into gcc compiler errors and better drop it
         # from the list below. Should be no problem as we don't
         # add the Qt module to our includes and therefore don't
         # need this path.
 
-        # QMAKE_CXXFLAGS += -isystem $$[QT_INSTALL_HEADERS]
-
         QMAKE_CXXFLAGS += \
             -isystem $$[QT_INSTALL_HEADERS]/QtCore \
             -isystem $$[QT_INSTALL_HEADERS]/QtGui \
@@ -114,13 +107,6 @@ linux-g++ | linux-g++-64 {
 
     # QMAKE_CXXFLAGS_RELEASE  *= -Ofast
     # QMAKE_CXXFLAGS_RELEASE  *= -Os
-
-    # Some versions ( here 2.31.1 ) of the BFD linker may generate shared
-    # libraries with corrupt symbol version info which leads to
-    # "invalid version 21" errors when the corrupt shared library is used. 
-    # One possible workaround is to use the gold linker instead.
-
-    # QMAKE_LFLAGS  *= -Wl,-fuse-ld=gold
 }
 
 pedantic {
@@ -172,8 +158,7 @@ sanitize {
 
     CONFIG += sanitizer 
     CONFIG += sanitize_address 
-    #CONFIG *= sanitize_memory 
-    CONFIG *= sanitize_undefined
+    # CONFIG *= sanitize_undefined
 
     linux-g++ | linux-g++-64 {
         #QMAKE_CXXFLAGS *= -fsanitize-address-use-after-scope
@@ -185,9 +170,6 @@ debug {
     DEFINES += ITEM_STATISTICS=1
 }
 
-# Help out Qt Creator
-ide: DEFINES += QT_IDE
-
 # DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x000000
 
 LOCAL_PRI=$$(QSK_LOCAL_PRI)
diff --git a/playground/images/Image.h b/playground/images/Image.h
index b3c9df96..3eaabe49 100644
--- a/playground/images/Image.h
+++ b/playground/images/Image.h
@@ -7,17 +7,18 @@
 
 #include "QskGlobal.h"
 
-#ifdef QT_NO_KEYWORDS
-
-// qquickimage_p.h uses emit
-#define emit Q_EMIT
-#include <private/qquickimage_p.h>
-#undef emit
+QSK_QT_PRIVATE_BEGIN
 
+#ifndef emit
+    #define emit
+    #include <private/qquickimage_p.h>
+    #undef emit
 #else
-#include <private/qquickimage_p.h>
+    #include <private/qquickimage_p.h>
 #endif
 
+QSK_QT_PRIVATE_END
+
 #include <memory>
 
 class Image : public QQuickImage
diff --git a/playground/shadows/BoxShadowNode.cpp b/playground/shadows/BoxShadowNode.cpp
index 0087fa58..f1a5ef1a 100644
--- a/playground/shadows/BoxShadowNode.cpp
+++ b/playground/shadows/BoxShadowNode.cpp
@@ -94,9 +94,7 @@ namespace
         bool updateMaterial = ( oldMaterial == nullptr )
             || newMaterial->compare( oldMaterial ) != 0;
 
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 12, 0 )
         updateMaterial |= state.isCachedMaterialDataDirty();
-#endif
 
         if ( updateMaterial )
         {
diff --git a/src/common/QskFunctions.cpp b/src/common/QskFunctions.cpp
index aa5870bc..ded47fa5 100644
--- a/src/common/QskFunctions.cpp
+++ b/src/common/QskFunctions.cpp
@@ -159,11 +159,7 @@ qreal qskHorizontalAdvance( const QFont& font, const QString& text )
 
 qreal qskHorizontalAdvance( const QFontMetricsF& fontMetrics, const QString& text )
 {
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 11, 0 )
     return fontMetrics.horizontalAdvance( text );
-#else
-    return fontMetrics.width( text );
-#endif
 }
 
 qreal qskFuzzyFloor( qreal value, qreal stepSize )
diff --git a/src/common/QskGlobal.h b/src/common/QskGlobal.h
index 56361c17..9bb265fe 100644
--- a/src/common/QskGlobal.h
+++ b/src/common/QskGlobal.h
@@ -17,15 +17,15 @@
 #ifdef QSK_DLL
 
 #if defined( QSK_MAKEDLL )     // create a DLL library
-#define QSK_EXPORT Q_DECL_EXPORT
+    #define QSK_EXPORT Q_DECL_EXPORT
 #else                        // use a DLL library
-#define QSK_EXPORT Q_DECL_IMPORT
+    #define QSK_EXPORT Q_DECL_IMPORT
 #endif
 
 #endif // QSK_DLL
 
 #ifndef QSK_EXPORT
-#define QSK_EXPORT
+    #define QSK_EXPORT
 #endif
 
 #define QSK_QT_PRIVATE_BEGIN \
@@ -39,10 +39,4 @@
 #define QSK_QT_PRIVATE_END \
     QT_WARNING_POP
 
-#ifdef Q_FALLTHROUGH
-#define QSK_FALLTHROUGH Q_FALLTHROUGH
-#else
-#define QSK_FALLTHROUGH
-#endif
-
 #endif
diff --git a/src/controls/QskListView.cpp b/src/controls/QskListView.cpp
index f0a30301..331f8f8b 100644
--- a/src/controls/QskListView.cpp
+++ b/src/controls/QskListView.cpp
@@ -8,10 +8,8 @@
 #include "QskColorFilter.h"
 #include "QskEvent.h"
 
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 9, 0 )
 #include <qguiapplication.h>
 #include <qstylehints.h>
-#endif
 
 #include <qmath.h>
 
diff --git a/src/inputpanel/QskInputPanel.cpp b/src/inputpanel/QskInputPanel.cpp
index c2eb0974..bcad0e63 100644
--- a/src/inputpanel/QskInputPanel.cpp
+++ b/src/inputpanel/QskInputPanel.cpp
@@ -455,7 +455,6 @@ void QskInputPanel::updateInputPanel( Qt::InputMethodQueries queries )
         setLocale( event.value( Qt::ImPreferredLanguage ).toLocale() );
     }
 
-#if QT_VERSION >= QT_VERSION_CHECK( 5, 7, 0 )
     if ( queries & Qt::ImInputItemClipRectangle )
     {
         /*
@@ -463,7 +462,6 @@ void QskInputPanel::updateInputPanel( Qt::InputMethodQueries queries )
             so that it does not hide the item.
          */
     }
-#endif
 }
 
 void QskInputPanel::updateLocale( const QLocale& locale )
diff --git a/src/src.pro b/src/src.pro
index 9358bdf2..a25be7da 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -12,8 +12,6 @@ DEPENDPATH *= $${QSK_SUBDIRS}
 # CONFIG += pinyin
 # CONFIG += hunspell
 
-# DEFINES += QSK_LAYOUT_COMPAT
-
 HEADERS += \
     common/QskArcMetrics.h \
     common/QskAspect.h \