diff --git a/README.md b/README.md
index 19f66ce..986bb2e 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,8 @@ MyBB is the free and open source forum software powering thousands of engaging,
     * The database credentials are send to the admin be email.
 
 * How to upgrade:
-    * `https://www.domain.ltd/mybb/install/upgrade.php` and follow the post install.
+	* Remove the lock file `sudo rm /var/www/mybb/install/lock`
+    * and follow the post install `https://www.domain.ltd/mybb/install/upgrade.php`
 
 ## Documentation and resources
 
diff --git a/README_fr.md b/README_fr.md
index 630cf93..cedd228 100644
--- a/README_fr.md
+++ b/README_fr.md
@@ -27,7 +27,8 @@ MyBB is the free and open source forum software powering thousands of engaging,
     * The database credentials are send to the admin be email.
 
 * How to upgrade:
-    * `https://www.domain.ltd/mybb/install/upgrade.php` and follow the post install.
+	* Remove the lock file `sudo rm /var/www/mybb/install/lock`
+    * and follow the post install `https://www.domain.ltd/mybb/install/upgrade.php`
 
 ## Documentations et ressources