diff --git a/doc/PRE_UPGRADE.d/0.107.48~ynh3.md b/doc/PRE_UPGRADE.d/0.107.48~ynh3.md
index 709a1ae..e50d061 100644
--- a/doc/PRE_UPGRADE.d/0.107.48~ynh3.md
+++ b/doc/PRE_UPGRADE.d/0.107.48~ynh3.md
@@ -1,3 +1,5 @@
+⚠️ **Important thing to do before upgrading:** if you enabled the "Enable DNS-over-HTTPS" option in your config panel, please disable it before upgrading, else the upgrade will fail! ⚠️
+
 From this 0.107.48~ynh3 version, some things have changed:  
 
 - port 53 is no longer exposed on the Internet by default, it's now a deliberate choice