diff --git a/update.sh b/update.sh
index 441e23d3..c21b996a 100755
--- a/update.sh
+++ b/update.sh
@@ -4,7 +4,12 @@ set -x
 
 nix flake update
 
-BUILD_ARGS=()
+BUILD_ARGS=(
+    "--extra-substituters"
+    "ssh://charlotte@sunspear.vanpetegem.me"
+    "--trusted-public-keys"
+    "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= sunspear-nix-cache:4mgL4qS7EweCug1gAFiZKgQK+xuoJMBYThIUE+kPX4s="
+)
 
 if [ -d "../nixpkgs" -a -z "${NO_LOCAL:-}" ]
 then