diff --git a/Classes/PHPExcel.php b/Classes/PHPExcel.php
index cc70286d..f60a15cf 100644
--- a/Classes/PHPExcel.php
+++ b/Classes/PHPExcel.php
@@ -607,6 +607,22 @@ class PHPExcel
 		return false;
 	}
 
+	/**
+	 * Check if style exists in style collection
+	 *
+	 * @param PHPExcel_Style $style
+	 * @return boolean
+	 */
+	public function cellXfExists($pCellStyle = null)
+	{
+		foreach ($this->_cellXfCollection as $cellXf) {
+			if ($cellXf === $pCellStyle) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	/**
 	 * Get default style
 	 *
diff --git a/Classes/PHPExcel/Worksheet.php b/Classes/PHPExcel/Worksheet.php
index bc58a696..4ffd94f3 100644
--- a/Classes/PHPExcel/Worksheet.php
+++ b/Classes/PHPExcel/Worksheet.php
@@ -1454,9 +1454,9 @@ class PHPExcel_Worksheet implements PHPExcel_IComparable
 
 		// Add the style to the workbook if necessary
 		$workbook = $this->_parent;
-		if ($existingStyle = $this->_parent->getCellXfByHashCode($pCellStyle->getHashCode())) {
-			// there is already such cell Xf in our collection
-			$xfIndex = $existingStyle->getIndex();
+		if ($this->_parent->cellXfExists($pCellStyle)) {
+			// there is already this cell Xf in our collection
+			$xfIndex = $pCellStyle->getIndex();
 		} else {
 			// we don't have such a cell Xf, need to add
 			$workbook->addCellXf($pCellStyle);