diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index 63a5eb8e..55694f10 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -1919,7 +1919,7 @@ class Xlsx extends BaseReader
                                     if (strpos((string) $definedName, '!') !== false) {
                                         // Extract sheet name
                                         $extractedSheetName = Worksheet::extractSheetTitle((string) $definedName, true);
-                                        $extractedSheetName = trim($extractedSheetName[0],"'");
+                                        $extractedSheetName = trim($extractedSheetName[0], "'");
 
                                         // Locate sheet
                                         $locatedSheet = $excel->getSheetByName($extractedSheetName);