diff --git a/Classes/PHPExcel/Style/Border.php b/Classes/PHPExcel/Style/Border.php
index 52aa76ea..b0e5a9e7 100644
--- a/Classes/PHPExcel/Style/Border.php
+++ b/Classes/PHPExcel/Style/Border.php
@@ -103,7 +103,7 @@ class PHPExcel_Style_Border extends PHPExcel_Style_Supervisor implements PHPExce
 	 * @param string $parentPropertyName
 	 * @return PHPExcel_Style_Border
 	 */
-	public function bindParent($parent, $parentPropertyName)
+	public function bindParent($parent, $parentPropertyName=NULL)
 	{
 		$this->_parent = $parent;
 		$this->_parentPropertyName = $parentPropertyName;
diff --git a/Classes/PHPExcel/Style/Color.php b/Classes/PHPExcel/Style/Color.php
index c8607d4f..ac004dba 100644
--- a/Classes/PHPExcel/Style/Color.php
+++ b/Classes/PHPExcel/Style/Color.php
@@ -98,7 +98,7 @@ class PHPExcel_Style_Color extends PHPExcel_Style_Supervisor implements PHPExcel
 	 * @param string $parentPropertyName
 	 * @return PHPExcel_Style_Color
 	 */
-	public function bindParent($parent, $parentPropertyName)
+	public function bindParent($parent, $parentPropertyName=NULL)
 	{
 		$this->_parent = $parent;
 		$this->_parentPropertyName = $parentPropertyName;
diff --git a/Classes/PHPExcel/Style/Supervisor.php b/Classes/PHPExcel/Style/Supervisor.php
index 7e6ca1ec..e91f2252 100644
--- a/Classes/PHPExcel/Style/Supervisor.php
+++ b/Classes/PHPExcel/Style/Supervisor.php
@@ -68,7 +68,7 @@ abstract class PHPExcel_Style_Supervisor
 	 * @param PHPExcel $parent
 	 * @return PHPExcel_Style_Supervisor
 	 */
-	public function bindParent($parent)
+	public function bindParent($parent, $parentPropertyName=NULL)
 	{
 		$this->_parent = $parent;
 		return $this;