diff --git a/manifest.json b/manifest.json
index 4891316..6a42fb3 100644
--- a/manifest.json
+++ b/manifest.json
@@ -38,6 +38,11 @@
                 "example": "/hydrogen",
                 "default": "/hydrogen"
             },
+            {
+                "name": "is_public",
+                "type": "boolean",
+                "default": true
+            },
             {
                 "name": "default_server",
                 "type": "string",
diff --git a/scripts/upgrade b/scripts/upgrade
index ca6851a..b9f889e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -92,6 +92,19 @@ chmod 750 "$final_path"
 chmod -R o-rwx "$final_path"
 chown -R $app:www-data "$final_path"
 
+#=================================================
+# SETUP SSOWAT
+#=================================================
+ynh_script_progression --message="Configuring permissions..." --time --weight=1
+
+# Make app public if necessary
+if [ $is_public -eq 1 ]
+then
+	# Everyone can access the app.
+	# The "main" permission is automatically created before the install script.
+	ynh_permission_update --permission="main" --add="visitors"
+fi
+
 #=================================================
 # NGINX CONFIGURATION
 #=================================================