diff --git a/src/drivers/Qt/ConsoleDebugger.cpp b/src/drivers/Qt/ConsoleDebugger.cpp
index 7d1dca0b..d2b190d7 100644
--- a/src/drivers/Qt/ConsoleDebugger.cpp
+++ b/src/drivers/Qt/ConsoleDebugger.cpp
@@ -37,6 +37,7 @@
 #include <QMenuBar>
 #include <QMenu>
 #include <QAction>
+#include <QActionGroup>
 #include <QGuiApplication>
 
 #include "../../types.h"
@@ -2986,7 +2987,7 @@ QAsmView::QAsmView(QWidget *parent)
 	//c = pal.color(QPalette::Base);
 	//printf("Base: R:%i  G:%i  B:%i \n", c.red(), c.green(), c.blue() );
 
-	//c = pal.color(QPalette::Background);
+	//c = pal.color(QPalette::Window);
 	//printf("BackGround: R:%i  G:%i  B:%i \n", c.red(), c.green(), c.blue() );
 
 	// Figure out if we are using a light or dark theme by checking the 
@@ -3003,13 +3004,13 @@ QAsmView::QAsmView(QWidget *parent)
 	if ( useDarkTheme )
 	{
 		pal.setColor(QPalette::Base      , fg );
-		pal.setColor(QPalette::Background, fg );
+		pal.setColor(QPalette::Window    , fg );
 		pal.setColor(QPalette::WindowText, bg );
 	}
 	else 
 	{
 		pal.setColor(QPalette::Base      , bg );
-		pal.setColor(QPalette::Background, bg );
+		pal.setColor(QPalette::Window    , bg );
 		pal.setColor(QPalette::WindowText, fg );
 	}
 
@@ -3877,7 +3878,7 @@ void QAsmView::paintEvent(QPaintEvent *event)
 	}
 	selAddr = parent->getBookmarkSelectedAddress();
 
-	painter.fillRect( 0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Background) );
+	painter.fillRect( 0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Window) );
 
 	y = pxLineSpacing;
 
diff --git a/src/drivers/Qt/ConsoleWindow.cpp b/src/drivers/Qt/ConsoleWindow.cpp
index 3e6480f7..3d9f7024 100644
--- a/src/drivers/Qt/ConsoleWindow.cpp
+++ b/src/drivers/Qt/ConsoleWindow.cpp
@@ -38,6 +38,7 @@
 #include <QDesktopServices>
 #include <QStyleFactory>
 #include <QApplication>
+#include <QActionGroup>
 #include <QShortcut>
 #include <QUrl>
 
@@ -133,7 +134,11 @@ consoleWin_t::consoleWin_t(QWidget *parent)
 	setWindowIcon(QIcon(":fceux1.png"));
 
 	gameTimer  = new QTimer( this );
+#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+	mutex      = new QRecursiveMutex();
+#else
 	mutex      = new QMutex( QMutex::Recursive );
+#endif
 	emulatorThread = new emulatorThread_t();
 
 	connect(emulatorThread, &QThread::finished, emulatorThread, &QObject::deleteLater);
diff --git a/src/drivers/Qt/ConsoleWindow.h b/src/drivers/Qt/ConsoleWindow.h
index 215f57d4..1df682d3 100644
--- a/src/drivers/Qt/ConsoleWindow.h
+++ b/src/drivers/Qt/ConsoleWindow.h
@@ -18,8 +18,11 @@
 #include <QKeyEvent>
 #include <QTimer>
 #include <QThread>
-#include <QMutex>
 #include <QCursor>
+#include <QMutex>
+#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+#include <QRecursiveMutex>
+#endif
 
 #include "Qt/ConsoleViewerGL.h"
 #include "Qt/ConsoleViewerSDL.h"
@@ -96,7 +99,11 @@ class  consoleWin_t : public QMainWindow
 
 		void setCyclePeriodms( int ms );
 
+#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+		QRecursiveMutex *mutex;
+#else
 		QMutex *mutex;
+#endif
 
 		void requestClose(void);
 
diff --git a/src/drivers/Qt/HexEditor.cpp b/src/drivers/Qt/HexEditor.cpp
index eadd0e52..d7482ace 100644
--- a/src/drivers/Qt/HexEditor.cpp
+++ b/src/drivers/Qt/HexEditor.cpp
@@ -34,6 +34,7 @@
 #include <QInputDialog>
 #include <QMessageBox>
 #include <QPushButton>
+#include <QActionGroup>
 
 #include "../../types.h"
 #include "../../fceu.h"
@@ -1847,7 +1848,7 @@ QHexEdit::QHexEdit(QWidget *parent)
 
 	pal = this->palette();
 	pal.setColor(QPalette::Base      , bg );
-	pal.setColor(QPalette::Background, bg );
+	pal.setColor(QPalette::Window    , bg );
 	pal.setColor(QPalette::WindowText, fg );
 
 	//editor->setAutoFillBackground(true);
@@ -1980,7 +1981,7 @@ void QHexEdit::setForeGroundColor( QColor fg )
 
 	pal = this->palette();
 	//pal.setColor(QPalette::Base      , Qt::black);
-	//pal.setColor(QPalette::Background, Qt::black);
+	//pal.setColor(QPalette::Window   , Qt::black);
 	pal.setColor(QPalette::WindowText, fg );
 
 	this->setPalette(pal);
@@ -1992,7 +1993,7 @@ void QHexEdit::setBackGroundColor( QColor bg )
 
 	pal = this->palette();
 	//pal.setColor(QPalette::Base      , Qt::black);
-	pal.setColor(QPalette::Background, bg );
+	pal.setColor(QPalette::Window    , bg );
 	//pal.setColor(QPalette::WindowText, fg );
 
 	this->setPalette(pal);
@@ -3325,17 +3326,17 @@ int QHexEdit::getRomAddrColor( int addr, QColor &fg, QColor &bg )
 	QColor color, oppColor; 
 			
 	fg = this->palette().color(QPalette::WindowText);
-	bg = this->palette().color(QPalette::Background);
+	bg = this->palette().color(QPalette::Window    );
 
 	if ( reverseVideo )
 	{
-		color    = this->palette().color(QPalette::Background);
+		color    = this->palette().color(QPalette::Window    );
 		oppColor = this->palette().color(QPalette::WindowText);
 	}
 	else
 	{
 		color    = this->palette().color(QPalette::WindowText);
-		oppColor = this->palette().color(QPalette::Background);
+		oppColor = this->palette().color(QPalette::Window    );
 	}
 
 	if ( viewMode != MODE_NES_ROM )
@@ -3543,7 +3544,7 @@ void QHexEdit::paintEvent(QPaintEvent *event)
 		lineOffset = maxLineOffset;
 	}
 	
-	painter.fillRect( 0, 0, w, h, this->palette().color(QPalette::Background) );
+	painter.fillRect( 0, 0, w, h, this->palette().color(QPalette::Window) );
 
 	if ( cursorBlinkCount >= 5 )
 	{
diff --git a/src/drivers/Qt/NameTableViewer.cpp b/src/drivers/Qt/NameTableViewer.cpp
index 6c2c7c0b..190c54d5 100644
--- a/src/drivers/Qt/NameTableViewer.cpp
+++ b/src/drivers/Qt/NameTableViewer.cpp
@@ -24,6 +24,7 @@
 #include <QDir>
 #include <QMenu>
 #include <QAction>
+#include <QActionGroup>
 #include <QMenuBar>
 #include <QPainter>
 #include <QInputDialog>
diff --git a/src/drivers/Qt/RamSearch.cpp b/src/drivers/Qt/RamSearch.cpp
index bab1ad2c..85e0694e 100644
--- a/src/drivers/Qt/RamSearch.cpp
+++ b/src/drivers/Qt/RamSearch.cpp
@@ -31,6 +31,7 @@
 #include <QMenu>
 #include <QMenuBar>
 #include <QAction>
+#include <QActionGroup>
 #include <QHeaderView>
 #include <QCloseEvent>
 #include <QGroupBox>
@@ -1583,13 +1584,13 @@ QRamSearchView::QRamSearchView(QWidget *parent)
 	if (useDarkTheme)
 	{
 		pal.setColor(QPalette::Base, fg);
-		pal.setColor(QPalette::Background, fg);
+		pal.setColor(QPalette::Window, fg);
 		pal.setColor(QPalette::WindowText, bg);
 	}
 	else
 	{
 		pal.setColor(QPalette::Base, bg);
-		pal.setColor(QPalette::Background, bg);
+		pal.setColor(QPalette::Window, bg);
 		pal.setColor(QPalette::WindowText, fg);
 	}
 	this->setPalette(pal);
@@ -1869,7 +1870,7 @@ void QRamSearchView::paintEvent(QPaintEvent *event)
 		it++;
 	}
 
-	painter.fillRect(0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Background));
+	painter.fillRect(0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Window));
 
 	painter.setPen(this->palette().color(QPalette::WindowText));
 
diff --git a/src/drivers/Qt/TraceLogger.cpp b/src/drivers/Qt/TraceLogger.cpp
index 847b598d..886bb540 100644
--- a/src/drivers/Qt/TraceLogger.cpp
+++ b/src/drivers/Qt/TraceLogger.cpp
@@ -1186,13 +1186,13 @@ QTraceLogView::QTraceLogView(QWidget *parent)
 	if (useDarkTheme)
 	{
 		pal.setColor(QPalette::Base, fg);
-		pal.setColor(QPalette::Background, fg);
+		pal.setColor(QPalette::Window, fg);
 		pal.setColor(QPalette::WindowText, bg);
 	}
 	else
 	{
 		pal.setColor(QPalette::Base, bg);
-		pal.setColor(QPalette::Background, bg);
+		pal.setColor(QPalette::Window, bg);
 		pal.setColor(QPalette::WindowText, fg);
 	}
 
@@ -1977,7 +1977,7 @@ void QTraceLogView::paintEvent(QPaintEvent *event)
 
 	viewLines = nrow;
 
-	painter.fillRect(0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Background));
+	painter.fillRect(0, 0, viewWidth, viewHeight, this->palette().color(QPalette::Window));
 
 	painter.setPen(this->palette().color(QPalette::WindowText));
 
diff --git a/src/drivers/Qt/ppuViewer.cpp b/src/drivers/Qt/ppuViewer.cpp
index 67ef80a9..b3ccbc51 100644
--- a/src/drivers/Qt/ppuViewer.cpp
+++ b/src/drivers/Qt/ppuViewer.cpp
@@ -33,6 +33,7 @@
 #include <QMessageBox>
 #include <QHeaderView>
 #include <QTreeWidget>
+#include <QActionGroup>
 
 #include "../../types.h"
 #include "../../fceu.h"
diff --git a/src/ppu.cpp b/src/ppu.cpp
index 0d7451dc..01a03a79 100644
--- a/src/ppu.cpp
+++ b/src/ppu.cpp
@@ -1088,7 +1088,7 @@ static void RefreshLine(int lastpixel) {
 	uint32 vofs;
 	int X1;
 
-	register uint8 *P = Pline;
+	uint8 *P = Pline;
 	int lasttile = lastpixel >> 3;
 	int numtiles;
 	static int norecurse = 0;	// Yeah, recursion would be bad.
diff --git a/src/pputile.inc b/src/pputile.inc
index 86fea166..ce4a6d0e 100644
--- a/src/pputile.inc
+++ b/src/pputile.inc
@@ -1,12 +1,12 @@
 uint8 *C;
-register uint8 cc;
+uint8 cc;
 uint32 vadr;
 #ifdef PPU_VRC5FETCH
 uint8 tmpd;
 #endif
 
 #ifndef PPUT_MMC5SP
-	register uint8 zz;
+	uint8 zz;
 #else
 	uint8 xs, ys;
 	xs = X1;