diff --git a/src/gui/ControllerRackView.cpp b/src/gui/ControllerRackView.cpp
index d7d5ee8dee2..83e2165e130 100644
--- a/src/gui/ControllerRackView.cpp
+++ b/src/gui/ControllerRackView.cpp
@@ -78,15 +78,10 @@ ControllerRackView::ControllerRackView()
 	layout->addWidget( m_addButton );
 	this->setLayout( layout );
 
-	QMdiSubWindow * subWin = getGUI()->mainWindow()->addWindowedWidget( this );
+	SubWindow * subWin = getGUI()->mainWindow()->addWindowedWidget(this);
 
-	// TODO: Automate setting one of these, stop hardcoding title bar height
-	// Set dimensions for detached mode
 	setFixedWidth(350);
 	setMinimumHeight(200);
-	// Set dimensions for embedded mode
-	subWin->setFixedWidth(350);
-	subWin->setMinimumHeight(230);
 
 	// No maximize button
 	Qt::WindowFlags flags = subWin->windowFlags();
diff --git a/src/gui/MicrotunerConfig.cpp b/src/gui/MicrotunerConfig.cpp
index 783c65e2870..bf191d9e74f 100644
--- a/src/gui/MicrotunerConfig.cpp
+++ b/src/gui/MicrotunerConfig.cpp
@@ -202,13 +202,10 @@ MicrotunerConfig::MicrotunerConfig() :
 	this->setLayout(microtunerLayout);
 
 	// Add to the main window and setup fixed size etc.
-	QMdiSubWindow *subWin = getGUI()->mainWindow()->addWindowedWidget(this);
-
+	SubWindow *subWin = getGUI()->mainWindow()->addWindowedWidget(this);
 	subWin->setAttribute(Qt::WA_DeleteOnClose, false);
-	subWin->setMinimumWidth(300);
-	subWin->setMinimumHeight(300);
-	subWin->setMaximumWidth(500);
-	subWin->setMaximumHeight(700);
+	setMinimumSize(300, 300);
+	setMaximumSize(500, 700);
 	subWin->hide();
 
 	// No maximize button
diff --git a/src/gui/MidiCCRackView.cpp b/src/gui/MidiCCRackView.cpp
index a0b1496fb54..cef8898e760 100644
--- a/src/gui/MidiCCRackView.cpp
+++ b/src/gui/MidiCCRackView.cpp
@@ -49,7 +49,7 @@ MidiCCRackView::MidiCCRackView(InstrumentTrack * track) :
 	setWindowIcon(embed::getIconPixmap("midi_cc_rack"));
 	setWindowTitle(tr("MIDI CC Rack - %1").arg(m_track->name()));
 
-	QMdiSubWindow * subWin = getGUI()->mainWindow()->addWindowedWidget(this);
+	SubWindow * subWin = getGUI()->mainWindow()->addWindowedWidget(this);
 
 	// Remove maximize button
 	Qt::WindowFlags flags = subWin->windowFlags();
@@ -58,9 +58,8 @@ MidiCCRackView::MidiCCRackView(InstrumentTrack * track) :
 
 	// Adjust window attributes, sizing and position
 	subWin->setAttribute(Qt::WA_DeleteOnClose, false);
-	subWin->resize(350, 300);
-	subWin->setFixedWidth(350);
-	subWin->setMinimumHeight(300);
+	setFixedWidth(350);
+	setMinimumHeight(300);
 	subWin->hide();
 
 	// Main window layout
diff --git a/src/gui/MixerView.cpp b/src/gui/MixerView.cpp
index e34e4ecbb97..0c3808f6a09 100644
--- a/src/gui/MixerView.cpp
+++ b/src/gui/MixerView.cpp
@@ -169,17 +169,11 @@ MixerView::MixerView(Mixer* mixer) :
 	// adjust window size
 	layout()->invalidate();
 	resize(sizeHint());
-	if (parentWidget())
-	{
-		parentWidget()->resize(parentWidget()->sizeHint());
-	}
 	setFixedHeight(height());
+	layout()->setSizeConstraint(QLayout::SetMinimumSize);
 
 	// add ourself to workspace
 	QMdiSubWindow* subWin = mainWindow->addWindowedWidget(this);
-	layout()->setSizeConstraint(QLayout::SetMinimumSize);
-	subWin->layout()->setSizeConstraint(QLayout::SetMinAndMaxSize);
-	subWin->setFixedHeight(subWin->height());
 
 	parentWidget()->setAttribute(Qt::WA_DeleteOnClose, false);
 	parentWidget()->move(5, 310);
diff --git a/src/gui/SubWindow.cpp b/src/gui/SubWindow.cpp
index 533777d32ac..05d240aed63 100644
--- a/src/gui/SubWindow.cpp
+++ b/src/gui/SubWindow.cpp
@@ -38,6 +38,7 @@
 #include <QPushButton>
 #include <QWindow>
 #include <QStyleOption>
+#include <QLayout>
 
 #include "embed.h"
 
@@ -93,6 +94,8 @@ SubWindow::SubWindow(QWidget *parent, Qt::WindowFlags windowFlags) :
 	m_windowTitle->setAttribute( Qt::WA_TransparentForMouseEvents, true );
 	m_windowTitle->setGraphicsEffect( m_shadow );
 
+	layout()->setSizeConstraint(QLayout::SetMinAndMaxSize);
+
 	// Disable the minimize button and make sure that the custom window hint is set
 	setWindowFlags((this->windowFlags() & ~Qt::WindowMinimizeButtonHint) | Qt::CustomizeWindowHint);
 
@@ -518,4 +521,5 @@ bool SubWindow::eventFilter(QObject* obj, QEvent* event)
 	}
 }
 
+
 } // namespace lmms::gui
diff --git a/src/gui/instrument/InstrumentTrackWindow.cpp b/src/gui/instrument/InstrumentTrackWindow.cpp
index 7f598636534..f98a985d98c 100644
--- a/src/gui/instrument/InstrumentTrackWindow.cpp
+++ b/src/gui/instrument/InstrumentTrackWindow.cpp
@@ -283,7 +283,7 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 
 	updateInstrumentView();
 
-	QMdiSubWindow* subWin = getGUI()->mainWindow()->addWindowedWidget( this );
+	SubWindow* subWin = getGUI()->mainWindow()->addWindowedWidget( this );
 	Qt::WindowFlags flags = subWin->windowFlags();
 	if (!m_instrumentView->isResizable()) {
 		flags |= Qt::MSWindowsFixedSizeDialogHint;
@@ -293,8 +293,8 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 		// Does the same thing, for detached detached windows, for other OSs.
 		
 	} else {
-		subWin->setMaximumSize(m_instrumentView->maximumWidth() + 12, m_instrumentView->maximumHeight() + 208);
-		subWin->setMinimumSize(m_instrumentView->minimumWidth() + 12, m_instrumentView->minimumHeight() + 208);
+		setMaximumSize(m_instrumentView->maximumWidth() + 12, m_instrumentView->maximumHeight() + 208);
+		setMinimumSize(m_instrumentView->minimumWidth() + 12, m_instrumentView->minimumHeight() + 208);
 	}
 	flags &= ~Qt::WindowMaximizeButtonHint;
 	subWin->setWindowFlags( flags );
diff --git a/src/gui/widgets/TempoSyncBarModelEditor.cpp b/src/gui/widgets/TempoSyncBarModelEditor.cpp
index 5ff2332e051..31644b72398 100644
--- a/src/gui/widgets/TempoSyncBarModelEditor.cpp
+++ b/src/gui/widgets/TempoSyncBarModelEditor.cpp
@@ -202,11 +202,11 @@ void TempoSyncBarModelEditor::showCustom()
 	if(m_custom == nullptr)
 	{
 		m_custom = new MeterDialog(getGUI()->mainWindow()->workspace());
-		QMdiSubWindow * subWindow = getGUI()->mainWindow()->addWindowedWidget(m_custom);
+		SubWindow * subWindow = getGUI()->mainWindow()->addWindowedWidget(m_custom);
 		Qt::WindowFlags flags = subWindow->windowFlags();
 		flags &= ~Qt::WindowMaximizeButtonHint;
 		subWindow->setWindowFlags(flags);
-		subWindow->setFixedSize(subWindow->size());
+		setFixedSize(size());
 		m_custom->setWindowTitle("Meter");
 		m_custom->setModel(&model()->getCustomMeterModel());
 	}
diff --git a/src/gui/widgets/TempoSyncKnob.cpp b/src/gui/widgets/TempoSyncKnob.cpp
index 473cee28ca9..ced453d10bb 100644
--- a/src/gui/widgets/TempoSyncKnob.cpp
+++ b/src/gui/widgets/TempoSyncKnob.cpp
@@ -295,11 +295,11 @@ void TempoSyncKnob::showCustom()
 	if( m_custom == nullptr )
 	{
 		m_custom = new MeterDialog( getGUI()->mainWindow()->workspace() );
-		QMdiSubWindow * subWindow = getGUI()->mainWindow()->addWindowedWidget( m_custom );
+		SubWindow * subWindow = getGUI()->mainWindow()->addWindowedWidget(m_custom);
 		Qt::WindowFlags flags = subWindow->windowFlags();
 		flags &= ~Qt::WindowMaximizeButtonHint;
 		subWindow->setWindowFlags( flags );
-		subWindow->setFixedSize( subWindow->size() );
+		setFixedSize(size());
 		m_custom->setWindowTitle( "Meter" );
 		m_custom->setModel( &model()->m_custom );
 	}