diff --git a/pkgs/nix-portable/default.nix b/pkgs/nix-portable/default.nix
index 10b35104..bfbe5505 100644
--- a/pkgs/nix-portable/default.nix
+++ b/pkgs/nix-portable/default.nix
@@ -207,6 +207,8 @@ let
       echo "experimental-features = nix-command flakes" >> \$dir/conf/nix.conf
       echo "ignored-acls = security.selinux system.nfs4_acl" >> \$dir/conf/nix.conf
       echo "sandbox-paths = /bin/sh=\$dir/busybox/bin/busybox" >> \$dir/conf/nix.conf
+      echo "extra-substituters = https://jungle.bsc.es/cache">> \$dir/conf/nix.conf
+      echo "extra-trusted-public-keys = jungle.bsc.es:pEc7MlAT0HEwLQYPtpkPLwRsGf80ZI26aj29zMw/HH0=" >> \$dir/conf/nix.conf
 
       # configurable config
       echo "sandbox = \$NP_CONF_SANDBOX" >> \$dir/conf/nix.conf