diff --git a/apps/testing/lib/Provider/FakeTranslationProvider.php b/apps/testing/lib/Provider/FakeTranslationProvider.php
index cc2d13db646b7..4bb5836941054 100644
--- a/apps/testing/lib/Provider/FakeTranslationProvider.php
+++ b/apps/testing/lib/Provider/FakeTranslationProvider.php
@@ -24,6 +24,14 @@ public function getAvailableLanguages(): array {
 	}
 
 	public function translate(?string $fromLanguage, string $toLanguage, string $text): string {
-		return strrev($text);
+		return $this->mb_strrev($text);
+	}
+
+	protected function mb_strrev(string $str): string {
+		$r = '';
+		for ($i = mb_strlen($str); $i >= 0; $i--) {
+			$r .= mb_substr($str, $i, 1);
+		}
+		return $r;
 	}
 }