diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -116,7 +116,7 @@
 
 add_library(kcm_knote MODULE ${kcm_knotes_PART_SRCS} )
 
-target_link_libraries(kcm_knote knotesprivate KF5::AkonadiCore  KF5::KCMUtils KF5::NewStuff KF5::WindowSystem notesharedprivate KF5::AkonadiNotes KF5::PimCommon KF5::I18n KF5::AkonadiWidgets)
+target_link_libraries(kcm_knote knotesprivate KF5::AkonadiCore  KF5::KCMUtils KF5::NewStuff notesharedprivate KF5::AkonadiNotes KF5::PimCommon KF5::I18n KF5::AkonadiWidgets)
 
 install(TARGETS kcm_knote DESTINATION ${KDE_INSTALL_PLUGINDIR})
 
diff --git a/src/apps/knotesapp.cpp b/src/apps/knotesapp.cpp
--- a/src/apps/knotesapp.cpp
+++ b/src/apps/knotesapp.cpp
@@ -56,7 +56,6 @@
 #include <KActionCollection>
 #include <KGlobalAccel>
 #include <KIconEffect>
-#include <KIconLoader>
 #include <KLocalizedString>
 #include <KMessageBox>
 #include <KWindowSystem>
@@ -72,6 +71,7 @@
 #include <QDBusConnection>
 #include <QFileDialog>
 #include <QMenu>
+#include <QStyle>
 
 static bool qActionLessThan(const QAction *a1, const QAction *a2)
 {
@@ -510,8 +510,7 @@
         connect(action, &QAction::triggered, this, &KNotesApp::slotShowNote);
         KIconEffect effect;
         QPixmap icon
-            = effect.apply(qApp->windowIcon().pixmap(IconSize(KIconLoader::Small),
-                                                     IconSize(KIconLoader::Small)),
+            = effect.apply(qApp->windowIcon().pixmap(style()->pixelMetric(QStyle::PM_SmallIconSize)),
                            KIconEffect::Colorize,
                            1,
                            note->palette().color(note->backgroundRole()),
diff --git a/src/configdialog/knoteconfigdialog.cpp b/src/configdialog/knoteconfigdialog.cpp
--- a/src/configdialog/knoteconfigdialog.cpp
+++ b/src/configdialog/knoteconfigdialog.cpp
@@ -31,10 +31,8 @@
 #include "print/knoteprintselectthemecombobox.h"
 
 #include <KAuthorized>
-#include <KIconLoader>
 #include <KLocalizedString>
 #include <KNS3/DownloadDialog>
-#include <KWindowSystem>
 
 #include <QCheckBox>
 #include <QApplication>
@@ -53,13 +51,6 @@
     button(QDialogButtonBox::Ok)->setDefault(true);
 
     setWindowTitle(title);
-    KWindowSystem::setIcons(winId(),
-                            qApp->windowIcon().pixmap(
-                                IconSize(KIconLoader::Desktop),
-                                IconSize(KIconLoader::Desktop)),
-                            qApp->windowIcon().pixmap(
-                                IconSize(KIconLoader::Small),
-                                IconSize(KIconLoader::Small)));
     addModule(QStringLiteral("knote_config_display"));
     addModule(QStringLiteral("knote_config_editor"));
     addModule(QStringLiteral("knote_config_action"));
diff --git a/src/configdialog/knotesimpleconfigdialog.cpp b/src/configdialog/knotesimpleconfigdialog.cpp
--- a/src/configdialog/knotesimpleconfigdialog.cpp
+++ b/src/configdialog/knotesimpleconfigdialog.cpp
@@ -27,10 +27,8 @@
 #include "attributes/notelockattribute.h"
 
 #include <KConfigGroup>
-#include <KIconLoader>
 #include <KLocalizedString>
 #include <KSharedConfig>
-#include <KWindowSystem>
 
 #include <QApplication>
 #include <QDialogButtonBox>
@@ -50,14 +48,6 @@
     connect(buttonBox, &QDialogButtonBox::accepted, this, &KNoteSimpleConfigDialog::accept);
     connect(buttonBox, &QDialogButtonBox::rejected, this, &KNoteSimpleConfigDialog::reject);
 
-    setWindowTitle(title);
-    KWindowSystem::setIcons(winId(),
-                            qApp->windowIcon().pixmap(
-                                IconSize(KIconLoader::Desktop),
-                                IconSize(KIconLoader::Desktop)),
-                            qApp->windowIcon().pixmap(
-                                IconSize(KIconLoader::Small),
-                                IconSize(KIconLoader::Small)));
     mTabWidget = new QTabWidget;
 
     mEditorConfigWidget = new KNoteEditorConfigWidget(this);
diff --git a/src/notes/knote.cpp b/src/notes/knote.cpp
--- a/src/notes/knote.cpp
+++ b/src/notes/knote.cpp
@@ -47,7 +47,6 @@
 #include <KComboBox>
 #include <KFileCustomDialog>
 #include <KIconEffect>
-#include <KIconLoader>
 #include <KLocalizedString>
 #include <KMessageBox>
 #include <KToggleAction>
@@ -938,14 +937,10 @@
     // aware of the new colors
     KIconEffect effect;
     const QColor col = mDisplayAttribute->backgroundColor();
-    const QPixmap icon = effect.apply(qApp->windowIcon().pixmap(
-                                          IconSize(KIconLoader::Desktop),
-                                          IconSize(KIconLoader::Desktop)),
+    const QPixmap icon = effect.apply(qApp->windowIcon().pixmap(style()->pixelMetric(QStyle::PM_MessageBoxIconSize)),
                                       KIconEffect::Colorize,
                                       1, col, false);
-    const QPixmap miniIcon = effect.apply(qApp->windowIcon().pixmap(
-                                              IconSize(KIconLoader::Small),
-                                              IconSize(KIconLoader::Small)),
+    const QPixmap miniIcon = effect.apply(qApp->windowIcon().pixmap(style()->pixelMetric(QStyle::PM_SmallIconSize)),
                                           KIconEffect::Colorize,
                                           1, col, false);
     KWindowSystem::setIcons(winId(), icon, miniIcon);
@@ -1022,13 +1017,9 @@
 
     // update the icon color
     KIconEffect effect;
-    QPixmap icon = effect.apply(qApp->windowIcon().pixmap(
-                                    IconSize(KIconLoader::Desktop),
-                                    IconSize(KIconLoader::Desktop)),
+    QPixmap icon = effect.apply(qApp->windowIcon().pixmap(style()->pixelMetric(QStyle::PM_MessageBoxIconSize)),
                                 KIconEffect::Colorize, 1, bg, false);
-    QPixmap miniIcon = effect.apply(qApp->windowIcon().pixmap(
-                                        IconSize(KIconLoader::Small),
-                                        IconSize(KIconLoader::Small)),
+    QPixmap miniIcon = effect.apply(qApp->windowIcon().pixmap(style()->pixelMetric(QStyle::PM_SmallIconSize)),
                                     KIconEffect::Colorize, 1, bg, false);
     KWindowSystem::setIcons(winId(), icon, miniIcon);
     // update the color of the title