diff --git a/Node/FunctionNode.php b/Node/FunctionNode.php
index 8428bac..938a82b 100644
--- a/Node/FunctionNode.php
+++ b/Node/FunctionNode.php
@@ -64,9 +64,7 @@ public function getSpecificity(): Specificity
 
     public function __toString(): string
     {
-        $arguments = implode(', ', array_map(function (Token $token) {
-            return "'".$token->getValue()."'";
-        }, $this->arguments));
+        $arguments = implode(', ', array_map(fn (Token $token) => "'".$token->getValue()."'", $this->arguments));
 
         return sprintf('%s[%s:%s(%s)]', $this->getNodeName(), $this->selector, $this->name, $arguments ? '['.$arguments.']' : '');
     }
diff --git a/Parser/Parser.php b/Parser/Parser.php
index d611efe..101df57 100644
--- a/Parser/Parser.php
+++ b/Parser/Parser.php
@@ -57,9 +57,7 @@ public static function parseSeries(array $tokens): array
             }
         }
 
-        $joined = trim(implode('', array_map(function (Token $token) {
-            return $token->getValue();
-        }, $tokens)));
+        $joined = trim(implode('', array_map(fn (Token $token) => $token->getValue(), $tokens)));
 
         $int = function ($string) {
             if (!is_numeric($string)) {
diff --git a/Tests/Parser/ParserTest.php b/Tests/Parser/ParserTest.php
index 48a67f5..919357b 100644
--- a/Tests/Parser/ParserTest.php
+++ b/Tests/Parser/ParserTest.php
@@ -25,9 +25,7 @@ public function testParser($source, $representation)
     {
         $parser = new Parser();
 
-        $this->assertEquals($representation, array_map(function (SelectorNode $node) {
-            return (string) $node->getTree();
-        }, $parser->parse($source)));
+        $this->assertEquals($representation, array_map(fn (SelectorNode $node) => (string) $node->getTree(), $parser->parse($source)));
     }
 
     /** @dataProvider getParserExceptionTestData */