diff --git a/scripts/upgrade b/scripts/upgrade
index 46c9387..b05f0bb 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -14,14 +14,18 @@ source /usr/share/yunohost/helpers
 #=================================================
 ynh_script_progression --message="Ensuring downward compatibility..."
 
-if [ -z ${nss3_nick:-} ]; then
-    nss3_nick=""
-    ynh_app_setting_set --app=$app --key=nss3_nick --value=""
-fi
-
-if [ -z ${nss3_password:-} ]; then
+if ynh_compare_current_package_version --comparison lt --version 1.7.0~ynh2
+then
+    nss3_nick="SignaturePDF"
+    ynh_app_setting_set --app=$app --key=nss3_nick --value=$nss3_nick
     nss3_password=$(ynh_string_random)
     ynh_app_setting_set --app=$app --key=nss3_password --value=$nss3_password
+
+    echo "# Digital signature configuration
+NSS3_DIRECTORY=$data_dir/nss/
+NSS3_PASSWORD=$nss3_password
+NSS3_NICK=$nss3_nick
+" >> $install_dir/config/config.ini
 fi
 
 #=================================================
@@ -29,7 +33,7 @@ fi
 #=================================================
 ynh_script_progression --message="Upgrading source files..." --weight=1
 
-	# Download, check integrity, uncompress and patch the source from app.src
+# Download, check integrity, uncompress and patch the source from app.src
 ynh_setup_source --dest_dir="$install_dir" --keep="config/config.ini"
 
 chmod -R o-rwx "$install_dir"