diff --git a/src/Gui/PreferencePages/DlgSettingsGeneral.cpp b/src/Gui/PreferencePages/DlgSettingsGeneral.cpp
index 9030ecd9e2..2d2830e60a 100644
--- a/src/Gui/PreferencePages/DlgSettingsGeneral.cpp
+++ b/src/Gui/PreferencePages/DlgSettingsGeneral.cpp
@@ -329,8 +329,9 @@ void DlgSettingsGeneral::loadSettings()
     }
 
     QAbstractItemModel* model = ui->Languages->model();
-    if (model)
+    if (model) {
         model->sort(0);
+    }
 
     addIconSizes(getCurrentIconSize());
 
@@ -425,18 +426,44 @@ void DlgSettingsGeneral::loadThemes()
 {
     ui->themesCombobox->clear();
 
-    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/MainWindow");
+    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath(
+        "User parameter:BaseApp/Preferences/MainWindow");
 
     QString currentTheme = QString::fromLatin1(hGrp->GetASCII("Theme", "").c_str());
 
     Application::Instance->prefPackManager()->rescan();
     auto packs = Application::Instance->prefPackManager()->preferencePacks();
+    QString currentStyleSheet = QString::fromLatin1(hGrp->GetASCII("StyleSheet", "").c_str());
+    QFileInfo fi(currentStyleSheet);
+    currentStyleSheet = fi.baseName();
+    QString themeClassic = QStringLiteral("classic");  // handle the upcoming name change
+    QString similarTheme;
+    QString packName;
     for (const auto& pack : packs) {
         if (pack.second.metadata().type() == "Theme") {
+            packName = QString::fromStdString(pack.first);
+            if (packName.contains(themeClassic, Qt::CaseInsensitive)) {
+                themeClassic = QString::fromStdString(pack.first);
+            }
+            if (packName.contains(currentStyleSheet, Qt::CaseInsensitive)) {
+                similarTheme = QString::fromStdString(pack.first);
+            }
             ui->themesCombobox->addItem(QString::fromStdString(pack.first));
         }
     }
 
+    if (currentTheme.isEmpty()) {
+        if (!currentStyleSheet.isEmpty()
+            && !similarTheme.isEmpty()) {  // a user upgrading from 0.21 or earlier
+            hGrp->SetASCII("Theme", similarTheme.toStdString());
+            currentTheme = QString::fromLatin1(hGrp->GetASCII("Theme", "").c_str());
+        }
+        else {  // a brand new user
+            hGrp->SetASCII("Theme", themeClassic.toStdString());
+            currentTheme = QString::fromLatin1(hGrp->GetASCII("Theme", "").c_str());
+        }
+    }
+
     int index = ui->themesCombobox->findText(currentTheme);
     if (index >= 0 && index < ui->themesCombobox->count()) {
         ui->themesCombobox->setCurrentIndex(index);