diff --git a/htdocs/admin/multicurrency.php b/htdocs/admin/multicurrency.php
index 408a1a35f2d..b82ae88f094 100644
--- a/htdocs/admin/multicurrency.php
+++ b/htdocs/admin/multicurrency.php
@@ -149,8 +149,8 @@ if ($action == 'add_currency') {			// Manual insertion of a rate
 
 		setEventMessages($langs->trans("SetupSaved"), null);
 	} else {
-		// Run the update
-		$result = $multicurrency->syncRates();
+		// Run the update o currency rate (this may updates database)
+		$result = $multicurrency->syncRates(0, 0, '');
 		if ($result > 0) {
 			setEventMessages($langs->trans("CurrencyRateSyncSucceed"), null, "mesgs");
 		} else {
diff --git a/htdocs/core/modules/modMultiCurrency.class.php b/htdocs/core/modules/modMultiCurrency.class.php
index 728e9f0b5d0..e7d2ded797a 100644
--- a/htdocs/core/modules/modMultiCurrency.class.php
+++ b/htdocs/core/modules/modMultiCurrency.class.php
@@ -145,19 +145,19 @@ class modMultiCurrency extends DolibarrModules
 
 		$this->cronjobs = array(
 			0 => array(
-				'priority'=>61,
-				'label'=>$langs->trans('MutltiCurrencyAutoUpdateCurrencies'),
-				'jobtype'=>'method',
-				'class'=>'multicurrency/class/multicurrency.class.php',
-				'objectname'=>'MultiCurrency',
-				'method'=>'syncRates',
-				'parameters'=>'0,0,cron',
-				'comment'=>'Update all the currencies using the currencylayer API. An API key needs to be given in the multi-currency module config page to have this job working.<br>First param is not used, Second parameter is 0 to update only already existing currency defined into the Multicurrency module or 1 to add any currency. Third parameter must be "cron".',
-				'frequency'=>1,
-				'unitfrequency'=>2678400,
-				'status'=>$statusatinstall,
-				'test'=>'isModEnabled("cron")',
-				'datestart'=>$datestart
+				'priority' => 61,
+				'label' => $langs->trans('MutltiCurrencyAutoUpdateCurrencies'),
+				'jobtype' => 'method',
+				'class' => 'multicurrency/class/multicurrency.class.php',
+				'objectname' => 'MultiCurrency',
+				'method' => 'syncRates',
+				'parameters' => '0,0,cron',
+				'comment' => 'Update all the currencies using the currencylayer API. An API key needs to be given in the multi-currency module config page to have this job working.<br>First param is not used, Second parameter is 0 to update only already existing currency defined into the Multicurrency module or 1 to add any currency. Third parameter must be "cron".',
+				'frequency' => 1,
+				'unitfrequency' => 2678400,
+				'status' => $statusatinstall,
+				'test' => 'isModEnabled("cron")',
+				'datestart' => $datestart
 			),
 		);
 
diff --git a/htdocs/multicurrency/class/multicurrency.class.php b/htdocs/multicurrency/class/multicurrency.class.php
index 69aa41f8cb2..fa280d81071 100644
--- a/htdocs/multicurrency/class/multicurrency.class.php
+++ b/htdocs/multicurrency/class/multicurrency.class.php
@@ -627,10 +627,10 @@ class MultiCurrency extends CommonObject
 	}
 
 	/**
-	 * With free account we can't set source then recalcul all rates to force another source.
+	 * With free account we can't set source to something else than US, to we recalculate all rates to force another source.
 	 * This modify the array &$TRate.
 	 *
-	 * @param   stdClass	$TRate	Object containing all currencies rates
+	 * @param   stdClass	$TRate	Object containing all currencies rates to recalculate
 	 * @return	int					-1 if KO, 0 if nothing, 1 if OK
 	 */
 	public function recalculRates(&$TRate)
@@ -657,12 +657,12 @@ class MultiCurrency extends CommonObject
 	/**
 	 * Sync rates from API
 	 *
-	 * @param 	int|string  $key                No more used
+	 * @param 	int			$nu	                No more used
 	 * @param   int 	    $addifnotfound      Add if not found
 	 * @param   string  	$mode				"" for standard use, "cron" to use it in a cronjob
 	 * @return  int								Return integer <0 if KO, >0 if OK, if mode = "cron" OK is 0
 	 */
-	public function syncRates($key = '', $addifnotfound = 0, $mode = "")
+	public function syncRates($nu = 0, $addifnotfound = 0, $mode = "")
 	{
 		global $db, $langs;
 
@@ -698,6 +698,7 @@ class MultiCurrency extends CommonObject
 				$TRate = $response->quotes;
 				//$timestamp = $response->timestamp;
 
+				// Recalculate rate and update it (or add it) into database
 				if ($this->recalculRates($TRate) >= 0) {
 					foreach ($TRate as $currency_code => $rate) {
 						$code = substr($currency_code, 3, 3);