diff --git a/xlsxwriter.class.php b/xlsxwriter.class.php
index 97c313a77..39f9ce584 100644
--- a/xlsxwriter.class.php
+++ b/xlsxwriter.class.php
@@ -19,6 +19,7 @@ class XLSXWriter
 	protected $company;
 	protected $description;
 	protected $keywords = array();
+	protected $tempdir;
 	
 	protected $current_sheet;
 	protected $sheets = array();
@@ -369,7 +370,7 @@ protected function writeCell(XLSXWriter_BuffererWriter &$file, $row_number, $col
 		if (!is_scalar($value) || $value==='') { //objects, array, empty
 			$file->write('<c r="'.$cell_name.'" s="'.$cell_style_idx.'"/>');
 		} elseif (is_string($value) && $value[0]=='='){
-			$file->write('<c r="'.$cell_name.'" s="'.$cell_style_idx.'" t="s"><f>'.self::xmlspecialchars($value).'</f></c>');
+			$file->write('<c r="'.$cell_name.'" s="'.$cell_style_idx.'" t="s"><f>'.self::xmlspecialchars(ltrim($value, '=')).'</f></c>');
 		} elseif ($num_format_type=='n_date') {
 			$file->write('<c r="'.$cell_name.'" s="'.$cell_style_idx.'" t="n"><v>'.intval(self::convert_date_time($value)).'</v></c>');
 		} elseif ($num_format_type=='n_datetime') {