diff --git a/scripts/upgrade b/scripts/upgrade
index 2381a7b..f405d83 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -15,4 +15,5 @@ sudo rm $final_path/update-ynh.php
 sudo chown -R www-data: $final_path/data/
 sudo chown -R www-data: $final_path/extensions/
 
+sudo apt-get update
 sudo apt-get install -y php5-gmp