diff --git a/kdecore/kernel/kcomponentdata.cpp b/kdecore/kernel/kcomponentdata.cpp
index b74e8a51..eb6e8de1 100644
--- a/kdecore/kernel/kcomponentdata.cpp
+++ b/kdecore/kernel/kcomponentdata.cpp
@@ -168,7 +168,6 @@ KStandardDirs *KComponentData::dirs() const
 {
     Q_ASSERT(d);
     d->lazyInit(*this);
-
     return d->dirs;
 }
 
@@ -176,7 +175,6 @@ const KSharedConfig::Ptr &KComponentData::config() const
 {
     Q_ASSERT(d);
     d->lazyInit(*this);
-
     return d->sharedConfig;
 }
 
diff --git a/kdecore/kernel/kcomponentdata_p.h b/kdecore/kernel/kcomponentdata_p.h
index f50aeebe..616ea946 100644
--- a/kdecore/kernel/kcomponentdata_p.h
+++ b/kdecore/kernel/kcomponentdata_p.h
@@ -31,7 +31,7 @@ class KComponentDataPrivate
 {
 public:
     KComponentDataPrivate(const KAboutData &aboutData_)
-        : dirs(0),
+        : dirs(nullptr),
         aboutData(aboutData_),
         refCount(1)
     {
@@ -40,7 +40,7 @@ public:
             shouldRemoveCatalog = true;
         } else {
             shouldRemoveCatalog = false;
-	}
+        }
     }
 
     ~KComponentDataPrivate()
diff --git a/kdecore/kernel/kglobal.cpp b/kdecore/kernel/kglobal.cpp
index 03cc88aa..351b4650 100644
--- a/kdecore/kernel/kglobal.cpp
+++ b/kdecore/kernel/kglobal.cpp
@@ -53,8 +53,8 @@ class KGlobalPrivate
 {
     public:
         inline KGlobalPrivate()
-            : locale(0),
-            charsets(0),
+            : locale(nullptr),
+            charsets(nullptr),
             localeIsFromFakeComponent(false)
         {
             // the umask is read here before any threads are created to avoid race conditions
@@ -66,9 +66,9 @@ class KGlobalPrivate
         inline ~KGlobalPrivate()
         {
             delete locale;
-            locale = 0;
+            locale = nullptr;
             delete charsets;
-            charsets = 0;
+            charsets = nullptr;
         }
 
         KComponentData activeComponent;
@@ -275,10 +275,9 @@ QString KGlobal::caption()
     } else if (d->mainComponent.isValid() && d->mainComponent.aboutData()) {
         // We have some about data ?
         return d->mainComponent.aboutData()->programName();
-    } else {
-        // Last resort : application name
-        return QCoreApplication::instance()->applicationName();
     }
+    // Last resort : application name
+    return QCoreApplication::applicationName();
 }
 
 /**
diff --git a/kdecore/kernel/ktoolinvocation.cpp b/kdecore/kernel/ktoolinvocation.cpp
index 23927c3f..9cd2e2c8 100644
--- a/kdecore/kernel/ktoolinvocation.cpp
+++ b/kdecore/kernel/ktoolinvocation.cpp
@@ -215,7 +215,7 @@ void KToolInvocation::invokeHelp(const QString &anchor,
     QString appname;
     QString docPath;
     if (_appname.isEmpty()) {
-        appname = QCoreApplication::instance()->applicationName();
+        appname = QCoreApplication::applicationName();
     } else {
         appname = _appname;
     }
diff --git a/kdeui/actions/kstandardaction.cpp b/kdeui/actions/kstandardaction.cpp
index d1f3763d..b4813deb 100644
--- a/kdeui/actions/kstandardaction.cpp
+++ b/kdeui/actions/kstandardaction.cpp
@@ -119,7 +119,7 @@ KAction *create(StandardAction id, const QObject *recvr, const char *slot, QObje
         else
           aboutData = KGlobal::aboutData();
         */
-        QString appName = (aboutData) ? aboutData->programName() : qApp->applicationName();
+        QString appName = (aboutData) ? aboutData->programName() : QCoreApplication::applicationName();
         sLabel = i18n( pInfo->psLabel, appName );
       }
        break;
diff --git a/kdeui/kernel/kapplication.cpp b/kdeui/kernel/kapplication.cpp
index 786b09d0..969dff31 100644
--- a/kdeui/kernel/kapplication.cpp
+++ b/kdeui/kernel/kapplication.cpp
@@ -292,7 +292,7 @@ QString KApplicationPrivate::sessionConfigName() const
     QString sessKey = q->sessionKey();
     if ( sessKey.isEmpty() && !sessionKey.isEmpty() )
         sessKey = sessionKey;
-    return QString::fromLatin1("session/%1_%2_%3").arg(q->applicationName()).arg(q->sessionId()).arg(sessKey);
+    return QString::fromLatin1("session/%1_%2_%3").arg(QCoreApplication::applicationName()).arg(q->sessionId()).arg(sessKey);
 }
 
 #ifdef Q_WS_X11
@@ -440,7 +440,7 @@ void KApplicationPrivate::init()
               reversedDomain.prepend(s);
           }
       const QString pidSuffix = QString::number( getpid() ).prepend( QLatin1String("-") );
-      const QString serviceName = reversedDomain + q->applicationName() + pidSuffix;
+      const QString serviceName = reversedDomain + QCoreApplication::applicationName() + pidSuffix;
       if ( bus->registerService(serviceName) == QDBusConnectionInterface::ServiceNotRegistered ) {
           kError() << "Couldn't register name '" << serviceName << "' with DBUS - another process owns it already!";
           ::exit(126);
@@ -456,7 +456,7 @@ void KApplicationPrivate::init()
 
   KSharedConfig::Ptr config = componentData.config();
   QByteArray readOnly = qgetenv("KDE_HOME_READONLY");
-  if (readOnly.isEmpty() && q->applicationName() != QLatin1String("kdialog"))
+  if (readOnly.isEmpty() && QCoreApplication::applicationName() != QLatin1String("kdialog"))
   {
     config->isConfigWritable(true);
   }
@@ -477,7 +477,7 @@ void KApplicationPrivate::init()
 
     // HACK: KLauncher creates KApplication instance and KToolInvocation creates KLauncher instance
     // (i.e recursion)
-    if (q->applicationName() != QLatin1String("klauncher")) {
+    if (QCoreApplication::applicationName() != QLatin1String("klauncher")) {
         q->connect(
             KToolInvocation::self(), SIGNAL(kapplication_hook(QStringList&,QByteArray&)),
             q, SLOT(_k_KToolInvocation_hook(QStringList&,QByteArray&))
diff --git a/kdeui/widgets/kmainwindow.cpp b/kdeui/widgets/kmainwindow.cpp
index 1516b675..399dd56f 100644
--- a/kdeui/widgets/kmainwindow.cpp
+++ b/kdeui/widgets/kmainwindow.cpp
@@ -352,7 +352,7 @@ void KMainWindowPrivate::polish(KMainWindow *q)
     q->winId(); // workaround for setWindowRole() crashing, and set also window role, just in case TT
     q->setWindowRole( s ); // will keep insisting that object name suddenly should not be used for window role
 
-    dbusName = '/' + qApp->applicationName() + '/' + q->objectName().replace(QLatin1Char('/'), QLatin1Char('_'));
+    dbusName = '/' + QCoreApplication::applicationName() + '/' + q->objectName().replace(QLatin1Char('/'), QLatin1Char('_'));
     // Clean up for dbus usage: any non-alphanumeric char should be turned into '_'
     const int len = dbusName.length();
     for ( int i = 0; i < len; ++i ) {