diff --git a/plasma/theme.cpp b/plasma/theme.cpp
index c7c9465f..1914e8c6 100644
--- a/plasma/theme.cpp
+++ b/plasma/theme.cpp
@@ -93,7 +93,13 @@ public:
         cacheTheme = config.cacheTheme();
 
         pixmapCache = new QSharedPointer<QCache<QString, QPixmap> >(new QCache<QString, QPixmap>());
+#ifndef QT_KATIE
         pixmapCache->data()->setMaxCost(config.themeCacheKb() * 1024);
+#else
+        // max cost is number of elements QCache can hold in Katie's implementation
+        const int reasonable = qMax(config.themeCacheKb() / 4, 100);
+        pixmapCache->data()->setMaxCost(reasonable);
+#endif
 
         saveTimer = new QTimer(q);
         saveTimer->setSingleShot(true);