diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6dbfcc961f..81e3fc2416 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,7 @@ set(PROJECT_VERSION "5.2.90")
 set(PROJECT_VERSION_MAJOR 5)
 
 cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
-set(QT_MIN_VERSION "5.3.0")
+set(QT_MIN_VERSION "5.4.0")
 set(KF5_MIN_VERSION "5.3.0")
 
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules ${CMAKE_MODULE_PATH} )
diff --git a/clients/aurorae/src/aurorae.cpp b/clients/aurorae/src/aurorae.cpp
index e24687d9cd..4ce2ee8bfc 100644
--- a/clients/aurorae/src/aurorae.cpp
+++ b/clients/aurorae/src/aurorae.cpp
@@ -47,16 +47,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QOpenGLFramebufferObject>
 #include <QPainter>
 #include <QQuickItem>
-
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 4, 0))
-#define HAVE_RENDER_CONTROL 1
-#else
-#define HAVE_RENDER_CONTROL 0
-#endif
-
-#if HAVE_RENDER_CONTROL
 #include <QQuickRenderControl>
-#endif
 #include <QQuickWindow>
 #include <QQmlComponent>
 #include <QQmlContext>
@@ -265,7 +256,6 @@ Decoration::Decoration(QObject *parent, const QVariantList &args)
     , m_extendedBorders(nullptr)
     , m_padding(nullptr)
     , m_themeName(s_defaultTheme)
-    , m_mutex(QMutex::Recursive)
 {
     m_themeName = findTheme(args);
     Helper::instance().ref();
@@ -274,7 +264,6 @@ Decoration::Decoration(QObject *parent, const QVariantList &args)
 Decoration::~Decoration()
 {
     Helper::instance().unref();
-#if HAVE_RENDER_CONTROL
     if (m_context) {
         m_context->makeCurrent(m_offscreenSurface.data());
 
@@ -285,7 +274,6 @@ Decoration::~Decoration()
 
         m_context->doneCurrent();
     }
-#endif
 }
 
 void Decoration::init()
@@ -293,19 +281,6 @@ void Decoration::init()
     KDecoration2::Decoration::init();
     auto s = settings();
     connect(s.data(), &KDecoration2::DecorationSettings::reconfigured, this, &Decoration::configChanged);
-    // recreate scene when compositing gets disabled, TODO: remove with rendercontrol
-#if !HAVE_RENDER_CONTROL
-    if (!m_recreateNonCompositedConnection) {
-        m_recreateNonCompositedConnection = connect(s.data(), &KDecoration2::DecorationSettings::alphaChannelSupportedChanged,
-                this, [this](bool alpha) {
-                    if (!alpha && m_item) {
-                        m_item->deleteLater();
-                        m_decorationWindow.reset();
-                        init();
-                    }
-                });
-    }
-#endif
 
     QQmlContext *context = new QQmlContext(Helper::instance().rootContext(), this);
     context->setContextProperty(QStringLiteral("decoration"), this);
@@ -346,7 +321,6 @@ void Decoration::init()
         m_item->setParentItem(visualParent.value<QQuickItem*>());
         visualParent.value<QQuickItem*>()->setProperty("drawBackground", false);
     } else {
-#if HAVE_RENDER_CONTROL
         // first create the context
         QSurfaceFormat format;
         format.setDepthBufferSize(16);
@@ -405,40 +379,6 @@ void Decoration::init()
         m_context->makeCurrent(m_offscreenSurface.data());
         m_renderControl->initialize(m_context.data());
         m_context->doneCurrent();
-#else
-        // we need a QQuickWindow till we depend on Qt 5.4
-        m_decorationWindow.reset(QWindow::fromWinId(client().data()->decorationId()));
-        m_view = new QQuickWindow(m_decorationWindow.data());
-        m_view->setFlags(Qt::WindowDoesNotAcceptFocus | Qt::WindowTransparentForInput);
-        m_view->setColor(Qt::transparent);
-        connect(m_view.data(), &QQuickWindow::beforeRendering, [this]() {
-            if (!settings()->isAlphaChannelSupported()) {
-                // directly render to QQuickWindow
-                m_fbo.reset();
-                return;
-            }
-            if (m_fbo.isNull() || m_fbo->size() != m_view->size()) {
-                m_fbo.reset(new QOpenGLFramebufferObject(m_view->size(), QOpenGLFramebufferObject::CombinedDepthStencil));
-                if (!m_fbo->isValid()) {
-                    qCWarning(AURORAE) << "Creating FBO as render target failed";
-                    m_fbo.reset();
-                    return;
-                }
-            }
-            m_view->setRenderTarget(m_fbo.data());
-        });
-        connect(m_view.data(), &QQuickWindow::afterRendering, [this] {
-            if (!m_fbo) {
-                return;
-            }
-            QMutexLocker locker(&m_mutex);
-            m_buffer = m_fbo->toImage();
-        });
-        connect(s.data(), &KDecoration2::DecorationSettings::alphaChannelSupportedChanged,
-                m_view.data(), &QQuickWindow::update);
-        connect(m_view.data(), &QQuickWindow::afterRendering, this, [this] { update(); }, Qt::QueuedConnection);
-        m_item->setParentItem(m_view->contentItem());
-#endif
     }
     setupBorders(m_item);
     if (m_extendedBorders) {
@@ -454,19 +394,12 @@ void Decoration::init()
     connect(client().data(), &KDecoration2::DecoratedClient::maximizedChanged, this, &Decoration::updateBorders, Qt::QueuedConnection);
     updateBorders();
     if (!m_view.isNull()) {
-#if !HAVE_RENDER_CONTROL
-        m_view->setVisible(true);
-#endif
         auto resizeWindow = [this] {
             QRect rect(QPoint(0, 0), size());
             if (m_padding && !client().data()->isMaximized()) {
                 rect = rect.adjusted(-m_padding->left(), -m_padding->top(), m_padding->right(), m_padding->bottom());
             }
             m_view->setGeometry(rect);
-#if !HAVE_RENDER_CONTROL
-            m_view->lower();
-            m_view->update();
-#endif
         };
         connect(this, &Decoration::bordersChanged, this, resizeWindow);
         connect(client().data(), &KDecoration2::DecoratedClient::widthChanged, this, resizeWindow);
@@ -513,12 +446,6 @@ void Decoration::updateBorders()
 void Decoration::paint(QPainter *painter, const QRect &repaintRegion)
 {
     Q_UNUSED(repaintRegion)
-#if !HAVE_RENDER_CONTROL
-    if (!settings()->isAlphaChannelSupported()) {
-        return;
-    }
-    QMutexLocker locker(&m_mutex);
-#endif
     painter->fillRect(rect(), Qt::transparent);
     QRectF r(QPointF(0, 0), m_buffer.size());
     bool updateShadow = false;
diff --git a/clients/aurorae/src/aurorae.h b/clients/aurorae/src/aurorae.h
index f6ef39ba2d..3b551488b5 100644
--- a/clients/aurorae/src/aurorae.h
+++ b/clients/aurorae/src/aurorae.h
@@ -21,7 +21,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KDecoration2/Decoration>
 #include <QElapsedTimer>
 #include <QVariant>
-#include <QMutex>
 #include <KCModule>
 
 class QOffscreenSurface;
@@ -32,7 +31,6 @@ class QQmlEngine;
 class QQuickItem;
 class QQuickRenderControl;
 class QQuickWindow;
-class QWindow;
 
 class KConfigLoader;
 
@@ -81,7 +79,6 @@ private:
     QMouseEvent translatedMouseEvent(QMouseEvent *orig);
     QScopedPointer<QOpenGLFramebufferObject> m_fbo;
     QImage m_buffer;
-    QScopedPointer<QWindow> m_decorationWindow;
     QPointer<QQuickWindow> m_view;
     QQuickItem *m_item;
     KWin::Borders *m_borders;
@@ -89,8 +86,6 @@ private:
     KWin::Borders *m_extendedBorders;
     KWin::Borders *m_padding;
     QString m_themeName;
-    QMutex m_mutex;
-    QMetaObject::Connection m_recreateNonCompositedConnection;
     QQuickRenderControl *m_renderControl = nullptr;
     QScopedPointer<QTimer> m_updateTimer;
     QScopedPointer<QOpenGLContext> m_context;
diff --git a/glxbackend.cpp b/glxbackend.cpp
index c97fbee474..adbc5e1b27 100644
--- a/glxbackend.cpp
+++ b/glxbackend.cpp
@@ -187,15 +187,6 @@ void GlxBackend::init()
     m_haveINTELSwapEvent    = hasGLExtension(QByteArrayLiteral("GLX_INTEL_swap_event"))
                                 && qgetenv("KWIN_USE_INTEL_SWAP_EVENT") == QByteArrayLiteral("1");
 
-    if (m_haveINTELSwapEvent) {
-        const QList<QByteArray> tokens = QByteArray(qVersion()).split('.');
-        uint32_t version = tokens[0].toInt() << 16 | tokens[1].toInt() << 8 | tokens[2].toInt();
-
-        // Qt 5.3 doesn't forward swap events to the native event filter
-        if (version < 0x00050400)
-            m_haveINTELSwapEvent = false;
-    }
-
     if (m_haveINTELSwapEvent) {
         m_swapEventFilter = std::make_unique<SwapEventFilter>(window, glxWindow);
         glXSelectEvent(display(), glxWindow, GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK);
diff --git a/libkwineffects/kwingltexture.cpp b/libkwineffects/kwingltexture.cpp
index 06c2ed8246..a27719332a 100644
--- a/libkwineffects/kwingltexture.cpp
+++ b/libkwineffects/kwingltexture.cpp
@@ -121,12 +121,10 @@ GLTexture::GLTexture(const QImage& image, GLenum target)
             { GL_RGB8,     GL_RGBA, GL_UNSIGNED_BYTE               }, // QImage::Format_RGBX8888
             { 0,           0,       0                              }, // QImage::Format_RGBA8888
             { GL_RGBA8,    GL_RGBA, GL_UNSIGNED_BYTE               }, // QImage::Format_RGBA8888_Premultiplied
-#if QT_VERSION >= QT_VERSION_CHECK(5, 4, 0)
             { GL_RGB10,    GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV }, // QImage::Format_BGR30
             { GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV }, // QImage::Format_A2BGR30_Premultiplied
             { GL_RGB10,    GL_BGRA, GL_UNSIGNED_INT_2_10_10_10_REV }, // QImage::Format_RGB30
             { GL_RGB10_A2, GL_BGRA, GL_UNSIGNED_INT_2_10_10_10_REV }, // QImage::Format_A2RGB30_Premultiplied
-#endif
         };
 
         QImage im;
diff --git a/workspace.cpp b/workspace.cpp
index dcf4479f58..7fbe16a10a 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -184,12 +184,6 @@ Workspace::Workspace(bool restore)
     // Select windowmanager privileges
     selectWmInputEventMask();
 
-#if QT_VERSION < 0x050302
-    // WORKAROUND: QXcbScreen before 5.3.2 overrides them, see bug #335926, QTBUG-39648
-    // TODO once we depend on Qt 5.4 remove it
-    connect(qApp, SIGNAL(screenAdded(QScreen*)), this, SLOT(selectWmInputEventMask()));
-#endif
-
     ScreenEdges::create(this);
 
     // VirtualDesktopManager needs to be created prior to init shortcuts