diff --git a/lib/private/Preview/TXT.php b/lib/private/Preview/TXT.php
index 0ae35fb3eec13..dbbc7480ef565 100644
--- a/lib/private/Preview/TXT.php
+++ b/lib/private/Preview/TXT.php
@@ -64,6 +64,8 @@ public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage {
 		if (trim($content) === '') {
 			return null;
 		}
+		
+		$content = mb_convert_encoding($content, 'UTF-8', 'auto');
 
 		$lines = preg_split("/\r\n|\n|\r/", $content);