diff --git a/sddmauthhelper.cpp b/sddmauthhelper.cpp
--- a/sddmauthhelper.cpp
+++ b/sddmauthhelper.cpp
@@ -17,6 +17,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "sddmauthhelper.h"
+#include "src/config.h"
 
 #include <unistd.h>
 
@@ -212,8 +213,8 @@
 ActionReply SddmAuthHelper::save(const QVariantMap &args)
 {
     ActionReply reply = ActionReply::HelperErrorReply();
-    QSharedPointer<KConfig> sddmConfig = openConfig(args[QStringLiteral("kde_settings.conf")].toString());
-    QSharedPointer<KConfig> sddmOldConfig = openConfig(args[QStringLiteral("sddm.conf")].toString());
+    QSharedPointer<KConfig> sddmConfig = openConfig(QString {QLatin1String(SDDM_CONFIG_DIR "/") + QStringLiteral("kde_settings.conf")});
+    QSharedPointer<KConfig> sddmOldConfig = openConfig(QLatin1String(SDDM_CONFIG_FILE));
     QSharedPointer<KConfig> themeConfig;
     QString themeConfigFile = args[QStringLiteral("theme.conf.user")].toString();
 
diff --git a/src/sddmkcm.h b/src/sddmkcm.h
--- a/src/sddmkcm.h
+++ b/src/sddmkcm.h
@@ -38,7 +38,6 @@
 
 private:
     KSharedConfigPtr mSddmConfig;
-    KSharedConfigPtr mSddmOldConfig;
     ThemeConfig *mThemeConfig;
     AdvancedConfig *mAdvancedConfig;
 };
diff --git a/src/sddmkcm.cpp b/src/sddmkcm.cpp
--- a/src/sddmkcm.cpp
+++ b/src/sddmkcm.cpp
@@ -54,8 +54,6 @@
 
     mSddmConfig = KSharedConfig::openConfig(QStringLiteral(SDDM_CONFIG_FILE), KConfig::CascadeConfig);
 
-    mSddmOldConfig = KSharedConfig::openConfig(QStringLiteral("sddm.conf"), KConfig::CascadeConfig);
-
     // This does not listen for new config files in the directory.
     QStringList configFiles = QDir(QLatin1String(SDDM_CONFIG_DIR)).entryList(QDir::Files | QDir::NoDotAndDotDot, QDir::LocaleAware),
                 systemConfigFiles = QDir(QLatin1String(SDDM_SYSTEM_CONFIG_DIR)).entryList(QDir::Files | QDir::NoDotAndDotDot, QDir::LocaleAware);
@@ -67,7 +65,6 @@
                     [](const QString &filename) -> QString { return QStringLiteral(SDDM_CONFIG_DIR "/") + filename; });
 
     mSddmConfig->addConfigSources(systemConfigFiles + configFiles);
-    mSddmOldConfig->addConfigSources(systemConfigFiles + configFiles);
 
     prepareUi();
 }
@@ -80,9 +77,6 @@
 {
     QVariantMap args;
 
-    args[QStringLiteral("kde_settings.conf")] = QString {QLatin1String(SDDM_CONFIG_DIR "/") + QStringLiteral("kde_settings.conf")};
-    args[QStringLiteral("sddm.conf")] = QLatin1String(SDDM_CONFIG_FILE);
-
     if (!mThemeConfig->themeConfigPath().isEmpty()) {
         args[QStringLiteral("theme.conf.user")] = QString(mThemeConfig->themeConfigPath() + QLatin1String(".user"));
     }