diff --git a/kcms/icons/main.h b/kcms/icons/main.h
--- a/kcms/icons/main.h
+++ b/kcms/icons/main.h
@@ -72,7 +72,7 @@
     Q_INVOKABLE void setIconSize(int group, int size);
     Q_INVOKABLE QList<int> availableIconSizes(int group) const;
 
-    Q_INVOKABLE QVariantList/*QList<QPixmap>*/ previewIcons(const QString &themeName, int size, qreal dpr) const;
+    Q_INVOKABLE QVariantList/*QList<QPixmap>*/ previewIcons(const QString &themeName, int size, qreal dpr);
 
 signals:
     void iconSizesChanged();
@@ -106,6 +106,9 @@
 
     QStringList m_iconGroups;
 
+    // ListView deletes and recreates delegates as you scroll, so once we generated previews, cache them
+    QHash<QString, QVariantList/*QList<QPixmap>*/> m_previewCache;
+
     QScopedPointer<QTemporaryFile> m_tempInstallFile;
 
     QPointer<KNS3::DownloadDialog> m_newStuffDialog;
diff --git a/kcms/icons/main.cpp b/kcms/icons/main.cpp
--- a/kcms/icons/main.cpp
+++ b/kcms/icons/main.cpp
@@ -477,8 +477,15 @@
     return everythingOk;
 }
 
-QVariantList IconModule::previewIcons(const QString &themeName, int size, qreal dpr) const
+QVariantList IconModule::previewIcons(const QString &themeName, int size, qreal dpr)
 {
+    const QString cacheKey = themeName + QLatin1Char('@') + QString::number(size) + QLatin1Char('@') + QString::number(dpr,'f',1);
+
+    auto it = m_previewCache.constFind(cacheKey);
+    if (it != m_previewCache.constEnd()) {
+        return *it;
+    }
+
     KIconTheme theme(themeName);
     QSvgRenderer renderer;
 
@@ -553,6 +560,8 @@
         return pixmapVariant.value<QPixmap>().isNull();
     }), pixmaps.end());
 
+    m_previewCache.insert(cacheKey, pixmaps);
+
     return pixmaps;
 }