diff --git a/applet.cpp b/applet.cpp
index 67c7020c7..e4bbef8d4 100644
--- a/applet.cpp
+++ b/applet.cpp
@@ -1022,7 +1022,7 @@ KPluginInfo::List Applet::knownAppletsForMimetype(const QString &mimetype)
     return KPluginInfo::fromServices(offers);
 }
 
-QStringList Applet::knownCategories(const QString &parentApp)
+QStringList Applet::knownCategories(const QString &parentApp, bool visibleOnly)
 {
     QString constraint = "exist [X-KDE-PluginInfo-Category]";
 
@@ -1034,8 +1034,13 @@ QStringList Applet::knownCategories(const QString &parentApp)
 
     KService::List offers = KServiceTypeTrader::self()->query("Plasma/Applet", constraint);
     QStringList categories;
-    foreach (KService::Ptr applet, offers) {
+    foreach (const KService::Ptr applet, offers) {
         QString appletCategory = applet->property("X-KDE-PluginInfo-Category").toString();
+        if (visibleOnly && applet->property("NoDisplay").toBool()) {
+            // we don't want to show the hidden category
+            continue;
+        }
+
         //kDebug() << "   and we have " << appletCategory;
         if (appletCategory.isEmpty()) {
             if (!categories.contains(i18n("Miscellaneous"))) {
diff --git a/applet.h b/applet.h
index 71ff8f35d..74bced14e 100644
--- a/applet.h
+++ b/applet.h
@@ -270,8 +270,9 @@ class PLASMA_EXPORT Applet : public Widget
          *                  list containing only applets not specifically
          *                  registered to an application.
          * @return list of categories
+         * @param visibleOnly true if it should only return applets that are marked as visible
          */
-        static QStringList knownCategories(const QString &parentApp = QString());
+        static QStringList knownCategories(const QString &parentApp = QString(), bool visibleOnly = true);
 
         /**
          * @return true if this plasmoid provides a GUI configuration