diff --git a/README.md b/README.md
index 006d620..10bf4e9 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ If you don't have YunoHost, please consult [the guide](https://yunohost.org/#/in
 
 Content management system (CMS) for simple website
 
-**Shipped version:** 0.8.20~ynh3
+**Shipped version:** 0.8.20~ynh4 *(:warning: This is the `testing` branch. The [`master` branch](https://github.com/YunoHost-Apps/yellow_ynh/tree/master) used in the catalog is currently on version 0.8.20\~ynh3.)*
 
 
 **Demo:** https://datenstrom.se/yellow/demo/
diff --git a/README_fr.md b/README_fr.md
index 6080af4..adae12b 100644
--- a/README_fr.md
+++ b/README_fr.md
@@ -17,7 +17,7 @@ Si vous n'avez pas YunoHost, regardez [ici](https://yunohost.org/#/install) pour
 
 Système de gestion de contenu (CMS) pour un site simple
 
-**Version incluse :** 0.8.20~ynh3
+**Version incluse :** 0.8.20~ynh4 *(:warning: Il s'agit de la branche `testing`. La [branche `master`](https://github.com/YunoHost-Apps/yellow_ynh/tree/master) utilisée dans le catalogue est actuellement en 0.8.20\~ynh3.)*
 
 
 **Démo :** https://datenstrom.se/yellow/demo/
diff --git a/manifest.json b/manifest.json
index a1ebbb8..58b5ce9 100644
--- a/manifest.json
+++ b/manifest.json
@@ -6,7 +6,7 @@
         "en": "Content management system (CMS) for simple website",
         "fr": "Système de gestion de contenu (CMS) pour un site simple"
     },
-    "version": "0.8.20~ynh3",
+    "version": "0.8.20~ynh4",
     "url": "https://datenstrom.se/yellow/",
     "upstream": {
         "license": "GPL-2.0-only",
diff --git a/scripts/upgrade b/scripts/upgrade
index 41b8db2..ca40f59 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -76,7 +76,7 @@ then
 	ynh_script_progression --message="Upgrading source files..." --weight=2
 
 	# Download, check integrity, uncompress and patch the source from app.src
-	ynh_setup_source --dest_dir="$final_path" --keep="content media"
+	ynh_setup_source --dest_dir="$final_path" --keep="content media system/extensions"
 fi
 
 chmod 750 "$final_path"