diff --git a/include/Model.h b/include/Model.h
index bc9f5c046..b40c21029 100644
--- a/include/Model.h
+++ b/include/Model.h
@@ -41,10 +41,6 @@ public:
 		m_displayName( _display_name ),
 		m_defaultConstructed( _default_constructed )
 	{
-#if QT_VERSION < 0x050000
-		connect( this, SIGNAL( dataChanged() ), this,
-			SLOT( thisDataChanged() ), Qt::DirectConnection );
-#endif
 	}
 
 	virtual ~Model()
@@ -89,19 +85,6 @@ signals:
 	// emitted if properties of the model (e.g. ranges) have changed
 	void propertiesChanged();
 
-#if QT_VERSION < 0x050000
-	// emitted along with dataChanged(), but with this model as an argument
-	// workaround for when QObject::sender() and Qt5 are unavailable
-	void dataChanged( Model * );
-
-private slots:
-	void thisDataChanged()
-	{
-		emit dataChanged( this );
-	}
-
-signals:
-#endif
 } ;
 
 
diff --git a/plugins/VstEffect/VstEffectControls.cpp b/plugins/VstEffect/VstEffectControls.cpp
index d92717d37..a0f97ce71 100644
--- a/plugins/VstEffect/VstEffectControls.cpp
+++ b/plugins/VstEffect/VstEffectControls.cpp
@@ -90,13 +90,8 @@ void VstEffectControls::loadSettings( const QDomElement & _this )
 				knobFModel[ i ]->setInitValue(LocaleHelper::toFloat(s_dumpValues.at(2)));
 			}
 
-#if QT_VERSION < 0x050000
-			connect( knobFModel[i], SIGNAL( dataChanged( Model * ) ),
-				this, SLOT( setParameter( Model * ) ), Qt::DirectConnection );
-#else
 			connect( knobFModel[i], &FloatModel::dataChanged, this,
 				[this, i]() { setParameter( knobFModel[i] ); }, Qt::DirectConnection);
-#endif
 		}
 
 	}
@@ -383,13 +378,8 @@ manageVSTEffectView::manageVSTEffectView( VstEffect * _eff, VstEffectControls *
 		}
 
 		FloatModel * model = m_vi->knobFModel[i];
-#if QT_VERSION < 0x050000
-		connect( model, SIGNAL( dataChanged( Model * ) ), this,
-			SLOT( setParameter( Model * ) ), Qt::DirectConnection );
-#else
 		connect( model, &FloatModel::dataChanged, this,
 			[this, model]() { setParameter( model ); }, Qt::DirectConnection);
-#endif
 		vstKnobs[ i ] ->setModel( model );
 	}
 
diff --git a/plugins/vestige/vestige.cpp b/plugins/vestige/vestige.cpp
index f4abed916..1d54538b6 100644
--- a/plugins/vestige/vestige.cpp
+++ b/plugins/vestige/vestige.cpp
@@ -223,13 +223,8 @@ void vestigeInstrument::loadSettings( const QDomElement & _this )
 				knobFModel[ i ]->setInitValue(LocaleHelper::toFloat(s_dumpValues.at(2)));
 			}
 
-#if QT_VERSION < 0x050000
-			connect( knobFModel[i], SIGNAL( dataChanged( Model * ) ),
-				this, SLOT( setParameter( Model * ) ), Qt::DirectConnection );
-#else
 			connect( knobFModel[i], &FloatModel::dataChanged, this,
 				[this, i]() { setParameter( knobFModel[i] ); }, Qt::DirectConnection);
-#endif
 		}
 	}
 	m_pluginMutex.unlock();
@@ -984,13 +979,8 @@ manageVestigeInstrumentView::manageVestigeInstrumentView( Instrument * _instrume
 		}
 
 		FloatModel * model = m_vi->knobFModel[i];
-#if QT_VERSION < 0x050000
-		connect( model, SIGNAL( dataChanged( Model * ) ), this,
-			SLOT( setParameter( Model * ) ), Qt::DirectConnection );
-#else
 		connect( model, &FloatModel::dataChanged, this,
 			[this, model]() { setParameter( model ); }, Qt::DirectConnection);
-#endif
 		vstKnobs[i] ->setModel( model );
 	}
 
diff --git a/plugins/zynaddsubfx/ZynAddSubFx.cpp b/plugins/zynaddsubfx/ZynAddSubFx.cpp
index fec5b3855..277c22596 100644
--- a/plugins/zynaddsubfx/ZynAddSubFx.cpp
+++ b/plugins/zynaddsubfx/ZynAddSubFx.cpp
@@ -291,10 +291,7 @@ void ZynAddSubFxInstrument::loadSettings( const QDomElement & _this )
 
 		emit settingsChanged();
 	}
-// FIXME: Remove this check in future versions.  Slots are public in Qt5+
-#if QT_VERSION >= 0x050000
 	emit instrumentTrack()->pitchModel()->dataChanged();
-#endif
 }
 
 
diff --git a/src/gui/SetupDialog.cpp b/src/gui/SetupDialog.cpp
index e8c7d5f82..f2ad13ee9 100644
--- a/src/gui/SetupDialog.cpp
+++ b/src/gui/SetupDialog.cpp
@@ -1075,12 +1075,7 @@ void SetupDialog::toggleOneInstrumentTrackWindow( bool _enabled )
 
 void SetupDialog::vstEmbedMethodChanged()
 {
-#if QT_VERSION >= 0x050000
 	m_vstEmbedMethod = m_vstEmbedComboBox->currentData().toString();
-#else
-	m_vstEmbedMethod = m_vstEmbedComboBox->itemData(
-			m_vstEmbedComboBox->currentIndex()).toString();
-#endif
 	m_vstAlwaysOnTopCheckBox->setVisible( m_vstEmbedMethod == "none" );
 }