diff --git a/kcm/src/collapsablebutton.cpp b/kcm/src/collapsablebutton.cpp
index 6be807e32254bff8d1fe0819bea579c6d14965c9..f4a3b2b96235b75635b8b62a393ee174503c46de 100644
--- a/kcm/src/collapsablebutton.cpp
+++ b/kcm/src/collapsablebutton.cpp
@@ -30,7 +30,7 @@
 CollapsableButton::CollapsableButton(const QString &text, QWidget *parent)
     : QWidget(parent)
     , mCollapsed(false)
-    , mWidget(0)
+    , mWidget(nullptr)
 {
     QHBoxLayout *layout = new QHBoxLayout(this);
     mLabel = new QLabel(text, this);
diff --git a/kcm/src/controlpanel.h b/kcm/src/controlpanel.h
index ec18646ceb5a9ac4170bfd1504acbec5101bec26..7bab7e4247d9aa895b239b73c0460ca6a6d8a22a 100644
--- a/kcm/src/controlpanel.h
+++ b/kcm/src/controlpanel.h
@@ -40,7 +40,7 @@ class ControlPanel : public QFrame
     Q_OBJECT
 
   public:
-    explicit ControlPanel(QWidget *parent = 0);
+    explicit ControlPanel(QWidget *parent = nullptr);
     virtual ~ControlPanel();
 
     void setConfig(const KScreen::ConfigPtr &config);
diff --git a/kcm/src/declarative/qmloutputcomponent.cpp b/kcm/src/declarative/qmloutputcomponent.cpp
index 98bf832f76a118dbf4537e4bdf15f2e9e8e55343..4dc683850aef673ba69b46a36b84cb40454c3424 100644
--- a/kcm/src/declarative/qmloutputcomponent.cpp
+++ b/kcm/src/declarative/qmloutputcomponent.cpp
@@ -44,16 +44,13 @@ QMLOutputComponent::~QMLOutputComponent()
 
 QMLOutput* QMLOutputComponent::createForOutput(const KScreen::OutputPtr &output)
 {
-    QObject *instance;
-
-    instance = beginCreate(m_engine->rootContext());
+    QObject *instance = beginCreate(m_engine->rootContext());
     if (!instance) {
         qWarning() << errorString();
-        return 0;
+        return nullptr;
     }
 
-    bool success = false;
-    success = instance->setProperty("outputPtr", QVariant::fromValue(output));
+    bool success = instance->setProperty("outputPtr", QVariant::fromValue(output));
     Q_ASSERT(success);
     success = instance->setProperty("screen", QVariant::fromValue(qobject_cast<QMLScreen*>(parent())));
     Q_ASSERT(success);
diff --git a/kcm/src/declarative/qmlscreen.cpp b/kcm/src/declarative/qmlscreen.cpp
index 6f443120715f71606b4c71875b06ebc72ea37541..5b8e2f91cafffe1d5b23594168559b920fdb37d7 100644
--- a/kcm/src/declarative/qmlscreen.cpp
+++ b/kcm/src/declarative/qmlscreen.cpp
@@ -33,13 +33,13 @@
 
 QMLScreen::QMLScreen(QQuickItem *parent):
     QQuickItem(parent),
-    m_config(0),
+    m_config(nullptr),
     m_connectedOutputsCount(0),
     m_enabledOutputsCount(0),
-    m_leftmost(0),
-    m_topmost(0),
-    m_rightmost(0),
-    m_bottommost(0)
+    m_leftmost(nullptr),
+    m_topmost(nullptr),
+    m_rightmost(nullptr),
+    m_bottommost(nullptr)
 {
     connect(this, &QMLScreen::widthChanged, this, &QMLScreen::viewSizeChanged);
     connect(this, &QMLScreen::heightChanged, this, &QMLScreen::viewSizeChanged);
diff --git a/kcm/src/declarative/qmlscreen.h b/kcm/src/declarative/qmlscreen.h
index d74fbbc76ef5183457e9fb9934719b501a2969bd..1c3d54b002686ade4c6247ef993475e445269fe7 100644
--- a/kcm/src/declarative/qmlscreen.h
+++ b/kcm/src/declarative/qmlscreen.h
@@ -56,7 +56,7 @@ class QMLScreen : public QQuickItem
                MEMBER m_engine)
 
   public:
-    explicit QMLScreen(QQuickItem *parent = 0);
+    explicit QMLScreen(QQuickItem *parent = nullptr);
     virtual ~QMLScreen();
 
 
@@ -111,8 +111,11 @@ class QMLScreen : public QQuickItem
     int m_connectedOutputsCount;
     int m_enabledOutputsCount;
 
-    QQmlEngine* m_engine;
-    QMLOutput *m_leftmost, *m_topmost, *m_rightmost, *m_bottommost;
+    QQmlEngine* m_engine = nullptr;
+    QMLOutput *m_leftmost = nullptr;
+    QMLOutput *m_topmost = nullptr;
+    QMLOutput *m_rightmost = nullptr;
+    QMLOutput *m_bottommost = nullptr;
 
 };
 
diff --git a/kcm/src/kcm_kscreen.h b/kcm/src/kcm_kscreen.h
index 93837c4d9c29b89db5b134d6b12dae975789e857..fc72ab859e48eccf9efd3ba76103eff99df90f1d 100644
--- a/kcm/src/kcm_kscreen.h
+++ b/kcm/src/kcm_kscreen.h
@@ -34,7 +34,7 @@ class KCMKScreen : public KCModule
     Q_OBJECT
 
   public:
-    explicit KCMKScreen (QWidget* parent = 0, const QVariantList& args = QVariantList());
+    explicit KCMKScreen (QWidget* parent = nullptr, const QVariantList& args = QVariantList());
     virtual ~KCMKScreen();
 
     virtual QSize sizeHint() const Q_DECL_OVERRIDE;
@@ -48,7 +48,7 @@ class KCMKScreen : public KCModule
   private:
     void configReady(KScreen::ConfigOperation *op);
 
-    Widget *mKScreenWidget;
+    Widget *mKScreenWidget = nullptr;
     bool m_blockChanges = false;
     QHBoxLayout *mMainLayout = nullptr;
 
diff --git a/kcm/src/outputconfig.h b/kcm/src/outputconfig.h
index 08535dfa7d007ebf9c2a2a244afd60257819e028..b85dfda49423e09bad10678af274394f8e093f6d 100644
--- a/kcm/src/outputconfig.h
+++ b/kcm/src/outputconfig.h
@@ -40,7 +40,7 @@ class OutputConfig : public QWidget
 
   public:
     explicit OutputConfig(QWidget *parent);
-    explicit OutputConfig(const KScreen::OutputPtr &output, QWidget *parent = 0);
+    explicit OutputConfig(const KScreen::OutputPtr &output, QWidget *parent = nullptr);
     virtual ~OutputConfig();
 
     virtual void setOutput(const KScreen::OutputPtr &output);
@@ -63,13 +63,13 @@ class OutputConfig : public QWidget
     virtual void initUi();
 
   protected:
-    QLabel *mTitle;
+    QLabel *mTitle = nullptr;
     KScreen::OutputPtr mOutput;
-    QCheckBox *mEnabled;
-    ResolutionSlider *mResolution;
-    QComboBox *mRotation;
-    QComboBox *mScale;
-    QComboBox *mRefreshRate;
+    QCheckBox *mEnabled = nullptr;
+    ResolutionSlider *mResolution = nullptr;
+    QComboBox *mRotation = nullptr;
+    QComboBox *mScale = nullptr;
+    QComboBox *mRefreshRate = nullptr;
     bool mShowScaleOption  = false;
 };
 
diff --git a/kcm/src/previewwidget.h b/kcm/src/previewwidget.h
index f0c07a833135e2a275a4156422c20002059454c5..7b81e9ca900ecbc29a574bbd2d73251674365f1f 100644
--- a/kcm/src/previewwidget.h
+++ b/kcm/src/previewwidget.h
@@ -28,7 +28,7 @@ class PreviewWidget : public QLabel
 {
     Q_OBJECT
 public:
-    PreviewWidget(QWidget *parent=0);
+    explicit PreviewWidget(QWidget *parent=nullptr);
     ~PreviewWidget();
     void setScale(qreal scale);
 public Q_SLOTS:
@@ -36,7 +36,7 @@ public Q_SLOTS:
 private:
     qreal pointSizeToPixelSize(qreal pointSize) const;
     qreal m_scale;
-    QWidget *m_internalPreview;
+    QWidget *m_internalPreview = nullptr;
 };
 
 #endif // PREVIEWWIDGET_H
diff --git a/kcm/src/primaryoutputcombo.h b/kcm/src/primaryoutputcombo.h
index 807753450341647aa038475664f6e0a608eb99c2..eb7a223a3b2c36c3ed51ae09daa14c2cd55129cc 100644
--- a/kcm/src/primaryoutputcombo.h
+++ b/kcm/src/primaryoutputcombo.h
@@ -30,7 +30,7 @@ class PrimaryOutputCombo : public QComboBox
 {
     Q_OBJECT
 public:
-    explicit PrimaryOutputCombo(QWidget *parent = 0);
+    explicit PrimaryOutputCombo(QWidget *parent = nullptr);
     virtual ~PrimaryOutputCombo();
 
     void setConfig(const KScreen::ConfigPtr &config);
@@ -55,4 +55,4 @@ private:
     KScreen::ConfigPtr mConfig;
 };
 
-#endif
\ No newline at end of file
+#endif
diff --git a/kcm/src/resolutionslider.h b/kcm/src/resolutionslider.h
index 0224416cf5ca27c67f10f5bf6667a306845323c0..403314dab6f9cb86cae87ba06085ab10c419a56c 100644
--- a/kcm/src/resolutionslider.h
+++ b/kcm/src/resolutionslider.h
@@ -36,7 +36,7 @@ class ResolutionSlider : public QWidget
     Q_OBJECT
 
   public:
-    explicit ResolutionSlider(const KScreen::OutputPtr &output, QWidget *parent = 0);
+    explicit ResolutionSlider(const KScreen::OutputPtr &output, QWidget *parent = nullptr);
     virtual ~ResolutionSlider();
 
     QSize currentResolution() const;
@@ -53,11 +53,11 @@ class ResolutionSlider : public QWidget
 
     QList<QSize> mModes;
 
-    QLabel *mSmallestLabel;
-    QLabel *mBiggestLabel;
-    QLabel *mCurrentLabel;
-    QSlider *mSlider;
-    QComboBox *mComboBox;
+    QLabel *mSmallestLabel = nullptr;
+    QLabel *mBiggestLabel = nullptr;
+    QLabel *mCurrentLabel = nullptr;
+    QSlider *mSlider = nullptr;
+    QComboBox *mComboBox = nullptr;
 };
 
 #endif // RESOLUTIONSLIDER_H
diff --git a/kcm/src/widget.cpp b/kcm/src/widget.cpp
index 248f5bdc0f6f7f6cd19780140424a4d0590f2bb1..b5a8ab12c5d7aa9f2337c6c512d02bf78f36617c 100644
--- a/kcm/src/widget.cpp
+++ b/kcm/src/widget.cpp
@@ -190,7 +190,7 @@ void Widget::setConfig(const KScreen::ConfigPtr &config)
     if (qmlOutput) {
         mScreen->setActiveOutput(qmlOutput);
     } else {
-        if (mScreen->outputs().count() > 0) {
+        if (!mScreen->outputs().isEmpty()) {
             mScreen->setActiveOutput(mScreen->outputs()[0]);
         }
     }
diff --git a/kcm/src/widget.h b/kcm/src/widget.h
index 326349a6db441ae8b68ebda781854b5e82bfc0db..d95df894444a47d6d3767d6ee0e2310b952ea7ac 100644
--- a/kcm/src/widget.h
+++ b/kcm/src/widget.h
@@ -46,7 +46,7 @@ class Widget : public QWidget
     Q_OBJECT
 
   public:
-    explicit Widget(QWidget *parent = 0);
+    explicit Widget(QWidget *parent = nullptr);
     virtual ~Widget();
 
     void setConfig(const KScreen::ConfigPtr &config);
@@ -80,23 +80,23 @@ class Widget : public QWidget
     KScreen::OutputPtr findOutput(const KScreen::ConfigPtr &config, const QVariantMap &info);
 
   private:
-    QMLScreen *mScreen;
+    QMLScreen *mScreen = nullptr;
     KScreen::ConfigPtr mConfig;
     KScreen::ConfigPtr mPrevConfig;
 
-    QQuickView *mDeclarativeView;
-    ControlPanel *mControlPanel;
+    QQuickView *mDeclarativeView = nullptr;
+    ControlPanel *mControlPanel = nullptr;
 
-    ProfilesModel *mProfilesModel;
-    PrimaryOutputCombo *mPrimaryCombo;
-    QComboBox *mProfilesCombo;
+    ProfilesModel *mProfilesModel = nullptr;
+    PrimaryOutputCombo *mPrimaryCombo = nullptr;
+    QComboBox *mProfilesCombo = nullptr;
 
-    QPushButton *mScaleAllOutputsButton;
-    QPushButton *mUnifyButton;
-    QPushButton *mSaveProfileButton;
+    QPushButton *mScaleAllOutputsButton = nullptr;
+    QPushButton *mUnifyButton = nullptr;
+    QPushButton *mSaveProfileButton = nullptr;
 
     QList<QQuickView*> mOutputIdentifiers;
-    QTimer *mOutputTimer;
+    QTimer *mOutputTimer = nullptr;
 
 };