diff --git a/src/Mutator/Extensions/MBString.php b/src/Mutator/Extensions/MBString.php
index adf45ea9c..287e851f5 100644
--- a/src/Mutator/Extensions/MBString.php
+++ b/src/Mutator/Extensions/MBString.php
@@ -111,7 +111,7 @@ private function setupConverters(array $functionsMap): void
             'mb_convert_case' => $this->mapConvertCase(),
         ];
 
-        $functionsToRemove = \array_filter($functionsMap, function ($isOn) {
+        $functionsToRemove = \array_filter($functionsMap, function($isOn) {
             return !$isOn;
         });
 
@@ -120,21 +120,21 @@ private function setupConverters(array $functionsMap): void
 
     private function mapName(string $functionName): callable
     {
-        return function (Node\Expr\FuncCall $node) use ($functionName): Generator {
+        return function(Node\Expr\FuncCall $node) use ($functionName): Generator {
             yield $this->createNode($node, $functionName, $node->args);
         };
     }
 
     private function mapNameSkipArg(string $functionName, int $skipArgs): callable
     {
-        return function (Node\Expr\FuncCall $node) use ($functionName, $skipArgs): Generator {
+        return function(Node\Expr\FuncCall $node) use ($functionName, $skipArgs): Generator {
             yield $this->createNode($node, $functionName, \array_slice($node->args, 0, $skipArgs));
         };
     }
 
     private function mapConvertCase(): callable
     {
-        return function (Node\Expr\FuncCall $node): Generator {
+        return function(Node\Expr\FuncCall $node): Generator {
             $modeValue = $this->getConvertCaseModeValue($node);
 
             if ($modeValue === null) {