diff --git a/htdocs/core/class/commondocgenerator.class.php b/htdocs/core/class/commondocgenerator.class.php
index 5799a1607e9..16eeab10ac4 100644
--- a/htdocs/core/class/commondocgenerator.class.php
+++ b/htdocs/core/class/commondocgenerator.class.php
@@ -1106,7 +1106,7 @@ abstract class CommonDocGenerator
 	public function getColumnContentXStart($colKey)
 	{
 		$colDef = $this->cols[$colKey];
-		return  $colDef['xStartPos'] + $colDef['content']['padding'][3];
+		return isset($colDef['xStartPos']) ? $colDef['xStartPos'] + $colDef['content']['padding'][3] : null;
 	}
 
 	/**