diff --git a/activities.cpp b/activities.cpp
index 48916801b5..01a6329892 100644
--- a/activities.cpp
+++ b/activities.cpp
@@ -71,7 +71,7 @@ void Activities::slotRemoved(const QString &activity)
         client->setOnActivity(activity, false);
     }
     //toss out any session data for it
-    KConfigGroup cg(KSharedConfig::openConfig(), QString("SubSession: ") + activity);
+    KConfigGroup cg(KSharedConfig::openConfig(), QByteArray("SubSession: ").append(activity.toUtf8()).constData());
     cg.deleteGroup();
 }
 
diff --git a/dbusinterface.cpp b/dbusinterface.cpp
index 3b210e1aab..0b13bf3517 100644
--- a/dbusinterface.cpp
+++ b/dbusinterface.cpp
@@ -188,7 +188,7 @@ QString CompositorDBusInterface::compositingType() const
         return QStringLiteral("gl2");
 #endif
     case QPainterCompositing:
-        return "qpainter";
+        return QStringLiteral("qpainter");
     case NoCompositing:
     default:
         return QStringLiteral("none");
diff --git a/egl_wayland_backend.cpp b/egl_wayland_backend.cpp
index 21a64491fb..912b22f563 100644
--- a/egl_wayland_backend.cpp
+++ b/egl_wayland_backend.cpp
@@ -78,21 +78,22 @@ EglWaylandBackend::~EglWaylandBackend()
 bool EglWaylandBackend::initializeEgl()
 {
     // Get the list of client extensions
-    const QByteArray clientExtensionString = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
-    if (clientExtensionString.isEmpty()) {
+    const char* clientExtensionsCString = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
+    const QByteArray clientExtensionsString = QByteArray::fromRawData(clientExtensionsCString, qstrlen(clientExtensionsCString));
+    if (clientExtensionsString.isEmpty()) {
         // If eglQueryString() returned NULL, the implementation doesn't support
         // EGL_EXT_client_extensions. Expect an EGL_BAD_DISPLAY error.
         (void) eglGetError();
     }
 
-    const QList<QByteArray> clientExtensions = clientExtensionString.split(' ');
+    const QList<QByteArray> clientExtensions = clientExtensionsString.split(' ');
 
     // Use eglGetPlatformDisplayEXT() to get the display pointer
     // if the implementation supports it.
-    m_havePlatformBase = clientExtensions.contains("EGL_EXT_platform_base");
+    m_havePlatformBase = clientExtensions.contains(QByteArrayLiteral("EGL_EXT_platform_base"));
     if (m_havePlatformBase) {
         // Make sure that the wayland platform is supported
-        if (!clientExtensions.contains("EGL_EXT_platform_wayland"))
+        if (!clientExtensions.contains(QByteArrayLiteral("EGL_EXT_platform_wayland")))
             return false;
 
         m_display = eglGetPlatformDisplayEXT(EGL_PLATFORM_WAYLAND_EXT, m_wayland->display(), nullptr);
@@ -171,11 +172,11 @@ bool EglWaylandBackend::initRenderingContext()
         EGL_NONE
     };
 
-    const QByteArray eglExtensions = eglQueryString(m_display, EGL_EXTENSIONS);
-    const QList<QByteArray> extensions = eglExtensions.split(' ');
+    const char* eglExtensionsCString = eglQueryString(m_display, EGL_EXTENSIONS);
+    const QList<QByteArray> extensions = QByteArray::fromRawData(eglExtensionsCString, qstrlen(eglExtensionsCString)).split(' ');
 
     // Try to create a 3.1 core context
-    if (options->glCoreProfile() && extensions.contains("EGL_KHR_create_context"))
+    if (options->glCoreProfile() && extensions.contains(QByteArrayLiteral("EGL_KHR_create_context")))
         m_context = eglCreateContext(m_display, m_config, EGL_NO_CONTEXT, context_attribs_31_core);
 
     if (m_context == EGL_NO_CONTEXT)
diff --git a/kcmkwin/kwindecoration/kcm.cpp b/kcmkwin/kwindecoration/kcm.cpp
index 3892ba1915..32848c9ef3 100644
--- a/kcmkwin/kwindecoration/kcm.cpp
+++ b/kcmkwin/kwindecoration/kcm.cpp
@@ -404,3 +404,4 @@ void ConfigurationModule::updateColors()
 }
 
 #include "kcm.moc"
+`
\ No newline at end of file
diff --git a/main_wayland.cpp b/main_wayland.cpp
index 892ae86be2..d8d67f65be 100644
--- a/main_wayland.cpp
+++ b/main_wayland.cpp
@@ -173,14 +173,14 @@ KWIN_EXPORT int kdemain(int argc, char * argv[])
     QByteArray xDisplay;
     QByteArray xServer;
     for (int i = 1; i < argc; ++i) {
-        QByteArray arg = argv[i];
+        QByteArray arg = QByteArray::fromRawData(argv[i], qstrlen(argv[i]));
         if (arg == "-x" || arg == "--x-server") {
             if (++i < argc) {
-                xServer = argv[i];
+                xServer = QByteArray::fromRawData(argv[i], qstrlen(argv[i]));
             }
-            startXephyr = (xServer == QStringLiteral("xephyr"));
-            startXvfb = (xServer == QStringLiteral("xvfb"));
-            startXwayland = (xServer == QStringLiteral("xwayland"));
+            startXephyr = (xServer == "xephyr");
+            startXvfb = (xServer == "xvfb");
+            startXwayland = (xServer == "xwayland");
             if (!startXephyr && !startXvfb && !startXwayland) {
                 fprintf(stderr, "%s: FATAL ERROR unknown X-Server %s specified to start\n",
                         argv[0], qPrintable(xServer));
@@ -190,7 +190,7 @@ KWIN_EXPORT int kdemain(int argc, char * argv[])
         }
         if (arg == "--display") {
             if (++i < argc) {
-                xDisplay = argv[i];
+                xDisplay = QByteArray::fromRawData(argv[i], qstrlen(argv[i]));
             }
         }
     }
@@ -257,7 +257,7 @@ KWIN_EXPORT int kdemain(int argc, char * argv[])
 
     // perform sanity checks
     // TODO: remove those two
-    if (a.platformName().toLower() != QStringLiteral("xcb")) {
+    if (a.platformName().toLower() != QLatin1String("xcb")) {
         fprintf(stderr, "%s: FATAL ERROR expecting platform xcb but got platform %s\n",
                 argv[0], qPrintable(a.platformName()));
         exit(1);