--- a/src/auth/Auth.cpp

+++ b/src/auth/Auth.cpp

@@ -129,7 +129,9 @@ namespace SDDM {

                 QStringList parts = in.readLine().split(QLatin1Char('='));

                 if (parts.size() >= 2) {

                     env.insert(parts[0], parts[1]);

-                    if (parts[0] == QLatin1String("LANG"))

+                    if (parts[0] == QLatin1String("LANG") &&

+                        (parts[1].startsWith(QStringLiteral("ru_"), Qt::CaseInsensitive) ||

+                         parts[1].startsWith(QStringLiteral("en_"), Qt::CaseInsensitive)))

                         langEmpty = false;

                 }

             }