diff --git a/src/PhpSpreadsheet/Writer/BaseWriter.php b/src/PhpSpreadsheet/Writer/BaseWriter.php
index afda5c43..d52b0d4a 100644
--- a/src/PhpSpreadsheet/Writer/BaseWriter.php
+++ b/src/PhpSpreadsheet/Writer/BaseWriter.php
@@ -108,7 +108,7 @@ abstract class BaseWriter implements IWriter
             return;
         }
 
-        $fileHandle = $filename ? fopen($filename, 'wb+') : false;
+        $fileHandle = $filename ? fopen($filename, 'wb') : false;
         if ($fileHandle === false) {
             throw new Exception('Could not open file "' . $filename . '" for writing.');
         }