diff --git a/containments/desktop/package/contents/config/main.xml b/containments/desktop/package/contents/config/main.xml
--- a/containments/desktop/package/contents/config/main.xml
+++ b/containments/desktop/package/contents/config/main.xml
@@ -91,8 +91,8 @@
       <default>true</default>
     </entry>
     <entry name="previewPlugins" type="StringList">
-      <label>List of id's of the thumbnail preview plugins to use in Folder View.</label>
-      <default>imagethumbnail,jpegthumbnail</default>
+      <label>List of ids of the thumbnail preview plugins to use in Folder View. If empty, uses a default set of thumbnailers (cf. KIO::PreviewJob::defaultPlugins)</label>
+      <default></default>
     </entry>
     <entry name="viewMode" type="Int">
       <label>The Folder View view mode (used only by the widget full represntation): 0 = Grid, 1 = List</label>
diff --git a/containments/desktop/plugins/folder/foldermodel.h b/containments/desktop/plugins/folder/foldermodel.h
--- a/containments/desktop/plugins/folder/foldermodel.h
+++ b/containments/desktop/plugins/folder/foldermodel.h
@@ -343,7 +343,11 @@
         bool m_sortDirsFirst;
         bool m_parseDesktopFiles;
         bool m_previews;
+        // An empty previewPlugin list means use default.
+        // We don't want to leak that fact to the QML side, however, so the property stays empty
+        // and internally we operate on effectivePreviewPlugins instead.
         QStringList m_previewPlugins;
+        QStringList m_effectivePreviewPlugins;
         FilterMode m_filterMode;
         QString m_filterPattern;
         bool m_filterPatternMatchAll;
diff --git a/containments/desktop/plugins/folder/foldermodel.cpp b/containments/desktop/plugins/folder/foldermodel.cpp
--- a/containments/desktop/plugins/folder/foldermodel.cpp
+++ b/containments/desktop/plugins/folder/foldermodel.cpp
@@ -70,6 +70,7 @@
 #include <KDirModel>
 #include <KIO/CopyJob>
 #include <KIO/Job>
+#include <KIO/PreviewJob>
 #include <KProtocolInfo>
 #include <KRun>
 
@@ -513,7 +514,7 @@
         if (m_viewAdapter && !m_previewGenerator) {
             m_previewGenerator = new KFilePreviewGenerator(abstractViewAdapter, this);
             m_previewGenerator->setPreviewShown(m_previews);
-            m_previewGenerator->setEnabledPlugins(m_previewPlugins);
+            m_previewGenerator->setEnabledPlugins(m_effectivePreviewPlugins);
         }
 
         emit viewAdapterChanged();
@@ -545,15 +546,23 @@
 
 void FolderModel::setPreviewPlugins(const QStringList& previewPlugins)
 {
-    if (m_previewPlugins != previewPlugins) {
-        m_previewPlugins = previewPlugins;
+    QStringList effectivePlugins = previewPlugins;
+    if (effectivePlugins.isEmpty()) {
+        effectivePlugins = KIO::PreviewJob::defaultPlugins();
+    }
+
+    if (m_effectivePreviewPlugins != effectivePlugins) {
+        m_effectivePreviewPlugins = effectivePlugins;
 
         if (m_previewGenerator) {
             m_previewGenerator->setPreviewShown(false);
-            m_previewGenerator->setEnabledPlugins(m_previewPlugins);
+            m_previewGenerator->setEnabledPlugins(m_effectivePreviewPlugins);
             m_previewGenerator->setPreviewShown(true);
         }
+    }
 
+    if (m_previewPlugins != previewPlugins) {
+        m_previewPlugins = previewPlugins;
         emit previewPluginsChanged();
     }
 }
diff --git a/containments/desktop/plugins/folder/previewpluginsmodel.cpp b/containments/desktop/plugins/folder/previewpluginsmodel.cpp
--- a/containments/desktop/plugins/folder/previewpluginsmodel.cpp
+++ b/containments/desktop/plugins/folder/previewpluginsmodel.cpp
@@ -22,6 +22,10 @@
 
 #include <KServiceTypeTrader>
 
+#include <KIO/PreviewJob>
+
+#include <algorithm>
+
 static bool lessThan(const KService::Ptr &a, const KService::Ptr &b)
 {
     return QString::localeAwareCompare(a->name(), b->name()) < 0;
@@ -92,9 +96,14 @@
 
 void PreviewPluginsModel::setCheckedPlugins(const QStringList &list)
 {
+    QStringList plugins = list;
+    if (plugins.isEmpty()) {
+        plugins = KIO::PreviewJob::defaultPlugins();
+    }
+
     m_checkedRows = QVector<bool>(m_plugins.size(), false);
 
-    foreach (const QString &name, list) {
+    for (const QString &name : plugins) {
         const int row = indexOfPlugin(name);
         if (row != -1) {
             m_checkedRows[row] = true;
@@ -114,5 +123,15 @@
             list.append(m_plugins.at(i)->desktopEntryName());
         }
     }
+
+    const QStringList defaultPlugins = KIO::PreviewJob::defaultPlugins();
+
+    // If the list of checked plugins is the default set, return an empty list
+    // which denotes the default set.
+    // This ensures newly installed thumbnails are always automatically enabled.
+    if (std::is_permutation(list.constBegin(), list.constEnd(), defaultPlugins.begin())) {
+        return QStringList();
+    }
+
     return list;
 }