diff --git a/synchro/synchro_exec.php b/synchro/synchro_exec.php
index 8b5a07520..e65814898 100644
--- a/synchro/synchro_exec.php
+++ b/synchro/synchro_exec.php
@@ -90,7 +90,6 @@ if (utils::IsModeCLI())
 {
 	$sAuthUser = ReadMandatoryParam($oP, 'auth_user', 'raw_data');
 	$sAuthPwd = ReadMandatoryParam($oP, 'auth_pwd', 'raw_data');
-	$sDataSourcesList = ReadMandatoryParam($oP, 'data_sources', 'raw_data'); // May contain commas
 	if (UserRights::CheckCredentials($sAuthUser, $sAuthPwd))
 	{
 		UserRights::Login($sAuthUser); // Login & set the user's language
@@ -137,14 +136,14 @@ else {
 		exit - 1;
 	}
 
-	$sDataSourcesList = ReadMandatoryParam($oP, 'data_sources', 'raw_data'); // May contain commas
-
-	if ($sDataSourcesList == null) {
-		UsageAndExit($oP);
-	}
 }
 
 $bSimulate = (utils::ReadParam('simulate', '0', true) == '1');
+$sDataSourcesList = ReadMandatoryParam($oP, 'data_sources', 'raw_data'); // May contain commas
+
+if ($sDataSourcesList == null) {
+	UsageAndExit($oP);
+}
 
 foreach(explode(',', $sDataSourcesList) as $iSDS)
 {