diff --git a/htdocs/langs/en_US/main.lang b/htdocs/langs/en_US/main.lang
index 5bb622544e7..1cc51fa7037 100644
--- a/htdocs/langs/en_US/main.lang
+++ b/htdocs/langs/en_US/main.lang
@@ -619,7 +619,7 @@ PrintContentArea=Show page to print main content area
 MenuManager=Menu manager
 WarningYouAreInMaintenanceMode=Warning, you are in a maintenance mode, so only login <b>%s</b> is allowed to use application at the moment.
 CoreErrorTitle=System error
-CoreErrorMessage=Sorry, an error occurred. Check the logs or contact your system administrator.
+CoreErrorMessage=Sorry, an error occurred. Contact your system administrator to check the logs or disable $dolibarr_main_prod=1 to get more information.
 CreditCard=Credit card
 FieldsWithAreMandatory=Fields with <b>%s</b> are mandatory
 FieldsWithIsForPublic=Fields with <b>%s</b> are shown on public list of members. If you don't want this, check off the "public" box.