diff --git a/lib/private/L10N/Factory.php b/lib/private/L10N/Factory.php
index f7d3fec4ff6..7361ab1a9dd 100644
--- a/lib/private/L10N/Factory.php
+++ b/lib/private/L10N/Factory.php
@@ -490,10 +490,14 @@ class Factory implements IFactory {
 				[$preferred_language] = explode(';', $preference);
 				$preferred_language = str_replace('-', '_', $preferred_language);
 
+				$preferred_language_parts = explode('_', $preferred_language);
 				foreach ($available as $available_language) {
 					if ($preferred_language === strtolower($available_language)) {
 						return $this->respectDefaultLanguage($app, $available_language);
 					}
+					if ($preferred_language_parts[0].'_'.$preferred_language_parts[count($preferred_language_parts) - 1] === strtolower($available_language)) {
+						return $available_language;
+					}
 				}
 
 				// Fallback from de_De to de