diff --git a/src/Spout/Common/Entity/Style/NumberFormat.php b/src/Spout/Common/Entity/Style/NumberFormat.php
index fe82032..33a167d 100644
--- a/src/Spout/Common/Entity/Style/NumberFormat.php
+++ b/src/Spout/Common/Entity/Style/NumberFormat.php
@@ -27,7 +27,7 @@ class NumberFormat
 
     private $currencySymbol;
 
-    private $commas;
+    private $commas = true;
 
     public function __construct(int $type = null)
     {
@@ -46,6 +46,16 @@ class NumberFormat
         return $this;
     }
 
+    /**
+     * @param bool $commas
+     * @return NumberFormat
+     */
+    public function setCommas($commas)
+    {
+        $this->commas = $commas;
+        return $this;
+    }
+
     /**
      * @return int|null
      */