diff --git a/scripts/install b/scripts/install
index 21db5d7..ea993d1 100755
--- a/scripts/install
+++ b/scripts/install
@@ -111,7 +111,7 @@ phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
 #=================================================
 ynh_script_progression --message="Configuring Castopod..." --weight=1
 
-redis_number=$(shuf -i 0-15 -n 1)
+redis_number=$(( $YNH_APP_INSTANCE_NUMBER - 1 ))
 ynh_add_config --template="../conf/.env.example" --destination="$final_path/.env"
 chmod 600 $final_path/.env
 chown $app:www-data "$final_path/.env"