diff --git a/scripts/config b/scripts/config
index c30d401..b3fd972 100644
--- a/scripts/config
+++ b/scripts/config
@@ -31,8 +31,10 @@ get__default_matrix_server() {
 
 set__default_matrix_server() {
 
+    old_value=${old[default_matrix_server]}
+
     # patching main.dart.js to replace the default matrix server
-    ynh_replace_string --match_string="=\"matrix.org\"" --replace_string="=\"$default_matrix_server\"" --target_file="$install_dir/main.dart.js"
+    ynh_replace_string --match_string="=\"$old_value\"" --replace_string="=\"$default_matrix_server\"" --target_file="$install_dir/main.dart.js"
 
     ynh_app_setting_set --app="$app" --key=default_matrix_server --value="$default_matrix_server"
 }