diff --git a/src/Glue/Gluer.php b/src/Glue/Gluer.php
index 7833ef9..99a1763 100644
--- a/src/Glue/Gluer.php
+++ b/src/Glue/Gluer.php
@@ -101,11 +101,9 @@ protected function changeWordsCase(array $words, int $caseMode): array
             return $words;
         }
 
-        $closure = static function (string $word) use ($caseMode): string {
-            return mb_convert_case($word, $caseMode, self::ENCODING);
-        };
+        $convertCase = static fn(string $word): string => mb_convert_case($word, $caseMode, self::ENCODING);
 
-        return array_map($closure, $words);
+        return array_map($convertCase, $words);
     }
 
     /**