diff --git a/Classes/PHPExcel/Chart/DataSeriesValues.php b/Classes/PHPExcel/Chart/DataSeriesValues.php
index 970c542a..ea6c4925 100644
--- a/Classes/PHPExcel/Chart/DataSeriesValues.php
+++ b/Classes/PHPExcel/Chart/DataSeriesValues.php
@@ -258,7 +258,7 @@ class PHPExcel_Chart_DataSeriesValues
 	}
 
 	public function refresh(PHPExcel_Worksheet $worksheet) {
-        if ($this->_dataSource !== NULL)
+        if ($this->_dataSource !== NULL) {
         	$calcEngine = PHPExcel_Calculation::getInstance();
 			$this->_dataValues = PHPExcel_Calculation::_unwrapResult(
 			    $calcEngine->_calculateFormulaValue(