diff --git a/kcms/icons/iconsizecategorymodel.h b/kcms/icons/iconsizecategorymodel.h
--- a/kcms/icons/iconsizecategorymodel.h
+++ b/kcms/icons/iconsizecategorymodel.h
@@ -25,6 +25,7 @@
     QString configKey;
     QString display;
     QString configSection;
+    int kIconloaderGroup;
 };
 
 Q_DECLARE_TYPEINFO(IconSizeCategoryModelData, Q_MOVABLE_TYPE);
@@ -39,7 +40,8 @@
 
     enum Roles {
         ConfigKeyRole = Qt::UserRole + 1,
-        ConfigSectionRole
+        ConfigSectionRole,
+        KIconLoaderGroupRole,
     };
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
diff --git a/kcms/icons/iconsizecategorymodel.cpp b/kcms/icons/iconsizecategorymodel.cpp
--- a/kcms/icons/iconsizecategorymodel.cpp
+++ b/kcms/icons/iconsizecategorymodel.cpp
@@ -18,16 +18,17 @@
 
 #include "iconsizecategorymodel.h"
 #include <KLocalizedString>
+#include <KIconLoader>
 
 IconSizeCategoryModel::IconSizeCategoryModel(QObject *parent)
     : QAbstractListModel(parent)
     , m_data({
-        {QStringLiteral("desktopSize"), I18N_NOOP("Desktop"), QStringLiteral("Desktop")},
-        {QStringLiteral("toolbarSize"), I18N_NOOP("Toolbar"), QStringLiteral("Toolbar")},
-        {QStringLiteral("mainToolbarSize"), I18N_NOOP("Main Toolbar"), QStringLiteral("MainToolbar")},
-        {QStringLiteral("smallSize"), I18N_NOOP("Small Icons"), QStringLiteral("Small")},
-        {QStringLiteral("panelSize"), I18N_NOOP("Panel"), QStringLiteral("Panel")},
-        {QStringLiteral("dialogSize"), I18N_NOOP("Dialogs"), QStringLiteral("Dialog")}
+        {QStringLiteral("desktopSize"), I18N_NOOP("Desktop"), QStringLiteral("Desktop"), KIconLoader::Desktop},
+        {QStringLiteral("toolbarSize"), I18N_NOOP("Toolbar"), QStringLiteral("Toolbar"), KIconLoader::Toolbar},
+        {QStringLiteral("mainToolbarSize"), I18N_NOOP("Main Toolbar"), QStringLiteral("MainToolbar"), KIconLoader::MainToolbar},
+        {QStringLiteral("smallSize"), I18N_NOOP("Small Icons"), QStringLiteral("Small"), KIconLoader::Small},
+        {QStringLiteral("panelSize"), I18N_NOOP("Panel"), QStringLiteral("Panel"), KIconLoader::Panel},
+        {QStringLiteral("dialogSize"), I18N_NOOP("Dialogs"), QStringLiteral("Dialog"), KIconLoader::Dialog}
     })
 {
 }
@@ -58,6 +59,8 @@
         return item.configKey;
     case ConfigSectionRole:
         return item.configSection;
+    case  KIconLoaderGroupRole:
+        return item.kIconloaderGroup;
     }
 
     return QVariant();
@@ -68,5 +71,6 @@
     QHash<int, QByteArray> roleNames = QAbstractListModel::roleNames();
     roleNames[ConfigKeyRole] = QByteArrayLiteral("configKey");
     roleNames[ConfigSectionRole] = QByteArrayLiteral("configSectionRole");
+    roleNames[KIconLoaderGroupRole] = QByteArrayLiteral("KIconLoaderGroup");
     return roleNames;
 }
diff --git a/kcms/icons/main.cpp b/kcms/icons/main.cpp
--- a/kcms/icons/main.cpp
+++ b/kcms/icons/main.cpp
@@ -140,15 +140,28 @@
 {
     bool needToExportToKDE4 = m_settings->isSaveNeeded();
 
+    // keep track of Group of icons size that has changed
+    QList<int> notifyList;
+    for (int i = 0; i < m_iconSizeCategoryModel->rowCount(); ++i) {
+        const QModelIndex index = m_iconSizeCategoryModel->index(i, 0);
+        const QString key = index.data(IconSizeCategoryModel::ConfigKeyRole).toString();
+        if (m_settings->findItem(key)->isSaveNeeded()) {
+            notifyList << index.data(IconSizeCategoryModel::KIconLoaderGroupRole).toInt();
+        }
+    }
+
     ManagedConfigModule::save();
 
     if (needToExportToKDE4) {
         exportToKDE4();
     }
 
     processPendingDeletions();
 
-    KIconLoader::global()->newIconLoader();
+    // Notify the group(s) where icon sizes have changed
+    for (auto group : qAsConst(notifyList)) {
+        KIconLoader::emitChange(KIconLoader::Group(group));
+    }
 }
 
 bool IconModule::isSaveNeeded() const
@@ -286,10 +299,8 @@
             QFile::remove(path);
         }
 
-        //message kde4 apps that icon theme is changed
+        //message kde4 apps that icon theme has changed
         for (int i = 0; i < KIconLoader::LastGroup; i++) {
-            KIconLoader::emitChange(KIconLoader::Group(i));
-
             QDBusMessage message = QDBusMessage::createSignal(QStringLiteral("/KGlobalSettings"),
                                                               QStringLiteral("org.kde.KGlobalSettings"),
                                                               QStringLiteral("notifyChange"));