diff --git a/korgac/alarmdialog.cpp b/korgac/alarmdialog.cpp
--- a/korgac/alarmdialog.cpp
+++ b/korgac/alarmdialog.cpp
@@ -267,7 +267,7 @@
 
     QWidget *suspendBox = new QWidget(topBox);
     QHBoxLayout *suspendBoxHBoxLayout = new QHBoxLayout(suspendBox);
-    suspendBoxHBoxLayout->setMargin(0);
+    suspendBoxHBoxLayout->setContentsMargins(0, 0, 0, 0);
     topLayout->addWidget(suspendBox);
 
     QLabel *l = new QLabel(i18nc("@label:spinbox", "Suspend &duration:"), suspendBox);
diff --git a/src/akonadicollectionview.cpp b/src/akonadicollectionview.cpp
--- a/src/akonadicollectionview.cpp
+++ b/src/akonadicollectionview.cpp
@@ -530,7 +530,7 @@
     mManagerShowCollectionProperties = new ManageShowCollectionProperties(this, this);
 
     QVBoxLayout *topLayout = new QVBoxLayout(this);
-    topLayout->setMargin(0);
+    topLayout->setContentsMargins(0, 0, 0, 0);
 
     QLineEdit *searchCol = new QLineEdit(this);
     searchCol->setToolTip(i18nc("info:tooltip", "Set search keyword"));
diff --git a/src/calendarview.cpp b/src/calendarview.cpp
--- a/src/calendarview.cpp
+++ b/src/calendarview.cpp
@@ -148,7 +148,7 @@
     mDateChecker = new DateChecker(this);
 
     QVBoxLayout *topLayout = new QVBoxLayout(this);
-    topLayout->setMargin(0);
+    topLayout->setContentsMargins(0, 0, 0, 0);
 
     // create the main layout frames.
     mPanner = new QSplitter(Qt::Horizontal, this);
@@ -170,15 +170,15 @@
 
     mEventViewerBox = new QWidget(mLeftSplitter);
     QVBoxLayout *mEventViewerBoxVBoxLayout = new QVBoxLayout(mEventViewerBox);
-    mEventViewerBoxVBoxLayout->setMargin(0);
-    mEventViewerBoxVBoxLayout->setMargin(0);
+    mEventViewerBoxVBoxLayout->setContentsMargins(0, 0, 0, 0);
+    mEventViewerBoxVBoxLayout->setContentsMargins(0, 0, 0, 0);
     mEventViewer = new CalendarSupport::IncidenceViewer(mCalendar.data(), mEventViewerBox);
     mEventViewer->setObjectName(QStringLiteral("EventViewer"));
     mEventViewerBoxVBoxLayout->addWidget(mEventViewer);
 
     QWidget *rightBox = new QWidget(mPanner);
     QVBoxLayout *rightBoxVBoxLayout = new QVBoxLayout(rightBox);
-    rightBoxVBoxLayout->setMargin(0);
+    rightBoxVBoxLayout->setContentsMargins(0, 0, 0, 0);
     mNavigatorBar = new NavigatorBar(rightBox);
     rightBoxVBoxLayout->addWidget(mNavigatorBar);
     mRightFrame = new QStackedWidget(rightBox);
diff --git a/src/dialog/noteeditdialog.cpp b/src/dialog/noteeditdialog.cpp
--- a/src/dialog/noteeditdialog.cpp
+++ b/src/dialog/noteeditdialog.cpp
@@ -66,9 +66,9 @@
     mOkButton->setEnabled(false);
 
     QGridLayout *layout = new QGridLayout(mainWidget);
-    layout->setMargin(0);
+    layout->setContentsMargins(0, 0, 0, 0);
     QHBoxLayout *hbox = new QHBoxLayout;
-    hbox->setMargin(0);
+    hbox->setContentsMargins(0, 0, 0, 0);
     hbox->setSpacing(2);
 
     mNoteTitle = new QLineEdit;
diff --git a/src/dialog/searchdialog.cpp b/src/dialog/searchdialog.cpp
--- a/src/dialog/searchdialog.cpp
+++ b/src/dialog/searchdialog.cpp
@@ -66,7 +66,7 @@
 
     // Results list view
     QVBoxLayout *layout = new QVBoxLayout;
-    layout->setMargin(0);
+    layout->setContentsMargins(0, 0, 0, 0);
     listView = new EventViews::ListView(m_calendarview->calendar(), this);
     layout->addWidget(listView);
     m_ui->listViewFrame->setLayout(layout);
diff --git a/src/kcmdesignerfields.cpp b/src/kcmdesignerfields.cpp
--- a/src/kcmdesignerfields.cpp
+++ b/src/kcmdesignerfields.cpp
@@ -295,7 +295,7 @@
 void KCMDesignerFields::initGUI()
 {
     QVBoxLayout *layout = new QVBoxLayout(this);
-    layout->setMargin(0);
+    layout->setContentsMargins(0, 0, 0, 0);
 
     bool noDesigner = QStandardPaths::findExecutable(QStringLiteral("designer")).isEmpty();
 
diff --git a/src/kontactplugin/korganizer/apptsummarywidget.cpp b/src/kontactplugin/korganizer/apptsummarywidget.cpp
--- a/src/kontactplugin/korganizer/apptsummarywidget.cpp
+++ b/src/kontactplugin/korganizer/apptsummarywidget.cpp
@@ -58,7 +58,7 @@
 {
     QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->setSpacing(3);
-    mainLayout->setMargin(3);
+    mainLayout->setContentsMargins(3, 3, 3, 3);
 
     QWidget *header = createHeader(
         this, QStringLiteral("view-calendar-upcoming-events"), i18n("Upcoming Events"));
diff --git a/src/kontactplugin/korganizer/todosummarywidget.cpp b/src/kontactplugin/korganizer/todosummarywidget.cpp
--- a/src/kontactplugin/korganizer/todosummarywidget.cpp
+++ b/src/kontactplugin/korganizer/todosummarywidget.cpp
@@ -58,7 +58,7 @@
 {
     QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->setSpacing(3);
-    mainLayout->setMargin(3);
+    mainLayout->setContentsMargins(3, 3, 3, 3);
 
     QWidget *header = createHeader(this, QStringLiteral("korg-todo"), i18n("Pending To-dos"));
     mainLayout->addWidget(header);
diff --git a/src/kontactplugin/specialdates/sdsummarywidget.cpp b/src/kontactplugin/specialdates/sdsummarywidget.cpp
--- a/src/kontactplugin/specialdates/sdsummarywidget.cpp
+++ b/src/kontactplugin/specialdates/sdsummarywidget.cpp
@@ -120,7 +120,7 @@
     // Create the Summary Layout
     QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->setSpacing(3);
-    mainLayout->setMargin(3);
+    mainLayout->setContentsMargins(3, 3, 3, 3);
 
     QWidget *header = createHeader(this,
                                    QStringLiteral("view-calendar-special-occasion"),
diff --git a/src/korganizer_part.cpp b/src/korganizer_part.cpp
--- a/src/korganizer_part.cpp
+++ b/src/korganizer_part.cpp
@@ -77,7 +77,7 @@
 
     QVBoxLayout *topLayout = new QVBoxLayout(canvas);
     topLayout->addWidget(mView);
-    topLayout->setMargin(0);
+    topLayout->setContentsMargins(0, 0, 0, 0);
 
     connect(mView, &CalendarView::incidenceSelected, this, &KOrganizerPart::slotChangeInfo);
 
diff --git a/src/prefs/koprefsdialog.cpp b/src/prefs/koprefsdialog.cpp
--- a/src/prefs/koprefsdialog.cpp
+++ b/src/prefs/koprefsdialog.cpp
@@ -249,7 +249,7 @@
         // holiday region selection
         QWidget *holidayRegBox = new QWidget(regionalPage);
         QHBoxLayout *holidayRegBoxHBoxLayout = new QHBoxLayout(holidayRegBox);
-        holidayRegBoxHBoxLayout->setMargin(0);
+        holidayRegBoxHBoxLayout->setContentsMargins(0, 0, 0, 0);
         holidaysLayout->addWidget(holidayRegBox, 1, 0, 1, 2);
 
         QLabel *holidayLabel = new QLabel(i18nc("@label", "Use holiday region:"), holidayRegBox);
@@ -1046,7 +1046,7 @@
     topTopLayout->addWidget(topFrame);
 
     QGridLayout *topLayout = new QGridLayout(topFrame);
-    topLayout->setMargin(0);
+    topLayout->setContentsMargins(0, 0, 0, 0);
 
     KPIM::KPrefsWidBool *useGroupwareBool
         = addWidBool(
@@ -1273,7 +1273,7 @@
 
     QWidget *buttonRow = new QWidget(this);
     QBoxLayout *buttonRowLayout = new QHBoxLayout(buttonRow);
-    buttonRowLayout->setMargin(0);
+    buttonRowLayout->setContentsMargins(0, 0, 0, 0);
     mConfigureButton = new QPushButton(buttonRow);
     KGuiItem::assign(mConfigureButton, KGuiItem(i18nc("@action:button", "Configure &Plugin..."),
                                                 QStringLiteral("configure"), QString(),
diff --git a/src/views/agendaview/koagendaview.cpp b/src/views/agendaview/koagendaview.cpp
--- a/src/views/agendaview/koagendaview.cpp
+++ b/src/views/agendaview/koagendaview.cpp
@@ -62,7 +62,7 @@
     , d(new Private(isSideBySide, this))
 {
     QHBoxLayout *layout = new QHBoxLayout(this);
-    layout->setMargin(0);
+    layout->setContentsMargins(0, 0, 0, 0);
     layout->addWidget(d->mAgendaView);
 
     connect(d->mAgendaView, &EventViews::AgendaView::zoomViewHorizontally,
diff --git a/src/views/monthview/monthview.cpp b/src/views/monthview/monthview.cpp
--- a/src/views/monthview/monthview.cpp
+++ b/src/views/monthview/monthview.cpp
@@ -37,7 +37,7 @@
     : KOEventView(parent)
 {
     QVBoxLayout *layout = new QVBoxLayout(this);
-    layout->setMargin(0);
+    layout->setContentsMargins(0, 0, 0, 0);
     mMonthView = new EventViews::MonthView(EventViews::MonthView::Visible, this);
     mMonthView->setPreferences(KOPrefs::instance()->eventViewsPreferences());
     layout->addWidget(mMonthView);
diff --git a/src/views/timelineview/kotimelineview.cpp b/src/views/timelineview/kotimelineview.cpp
--- a/src/views/timelineview/kotimelineview.cpp
+++ b/src/views/timelineview/kotimelineview.cpp
@@ -36,7 +36,7 @@
     : KOEventView(parent)
 {
     QVBoxLayout *vbox = new QVBoxLayout(this);
-    vbox->setMargin(0);
+    vbox->setContentsMargins(0, 0, 0, 0);
     mTimeLineView = new EventViews::TimelineView(this);
     vbox->addWidget(mTimeLineView);
     mEventPopup = eventPopup();
diff --git a/src/widgets/kdatenavigator.cpp b/src/widgets/kdatenavigator.cpp
--- a/src/widgets/kdatenavigator.cpp
+++ b/src/widgets/kdatenavigator.cpp
@@ -41,7 +41,7 @@
     , mBaseDate(1970, 1, 1)
 {
     QGridLayout *topLayout = new QGridLayout(this);
-    topLayout->setMargin(0);
+    topLayout->setContentsMargins(0, 0, 0, 0);
     topLayout->setSpacing(0);
 
     mNavigatorBar = new NavigatorBar(this);
diff --git a/src/widgets/navigatorbar.cpp b/src/widgets/navigatorbar.cpp
--- a/src/widgets/navigatorbar.cpp
+++ b/src/widgets/navigatorbar.cpp
@@ -81,7 +81,7 @@
 
     // set up control frame layout
     QHBoxLayout *ctrlLayout = new QHBoxLayout(this);
-    ctrlLayout->setMargin(0);
+    ctrlLayout->setContentsMargins(0, 0, 0, 0);
     ctrlLayout->addWidget(mPrevYear);
     ctrlLayout->addWidget(mPrevMonth);
     ctrlLayout->addStretch();