diff --git a/Classes/PHPExcel/Calculation/MathTrig.php b/Classes/PHPExcel/Calculation/MathTrig.php
index b2bb19d4..9f0e7f4c 100644
--- a/Classes/PHPExcel/Calculation/MathTrig.php
+++ b/Classes/PHPExcel/Calculation/MathTrig.php
@@ -880,9 +880,9 @@ class PHPExcel_Calculation_MathTrig {
 		$max		= PHPExcel_Calculation_Functions::flattenSingleValue($max);
 
 		if ($min == 0 && $max == 0) {
-			return (rand(0,10000000)) / 10000000;
+			return (mt_rand(0,10000000)) / 10000000;
 		} else {
-			return rand($min, $max);
+			return mt_rand($min, $max);
 		}
 	}	//	function RAND()
 
diff --git a/Examples/13calculation.php b/Examples/13calculation.php
index db149489..01e63ea7 100644
--- a/Examples/13calculation.php
+++ b/Examples/13calculation.php
@@ -34,6 +34,7 @@ date_default_timezone_set('Europe/London');
 define('EOL',(PHP_SAPI == 'cli') ? PHP_EOL : '<br />');
 
 date_default_timezone_set('Europe/London');
+mt_srand(1234567890);
 
 /** Include PHPExcel */
 require_once dirname(__FILE__) . '/../Classes/PHPExcel.php';
diff --git a/Examples/runall.php b/Examples/runall.php
index c65727eb..3818547a 100644
--- a/Examples/runall.php
+++ b/Examples/runall.php
@@ -59,6 +59,7 @@ $aTests = array(
 	, '11documentsecurity-xls.php'
 	, '12cellProtection.php'
 	, '13calculation.php'
+    , '13calculationCyclicFormulae.php'
 	, '14excel5.php'
 	, '15datavalidation.php'
 	, '15datavalidation-xls.php'