diff --git a/ci-tools/update-nixpkgs b/ci-tools/update-nixpkgs
index 4f13f43f3adeb7303dd96d82e81adaf4b3b7f16e..370184e720fd1c07f750bf34daf39bcaf5f854d9 100755
--- a/ci-tools/update-nixpkgs
+++ b/ci-tools/update-nixpkgs
@@ -36,7 +36,7 @@ setup_git() {
 setup_ssh
 setup_git
 
-TARGET_BRANCH="nixpkgs-upgrade-$(date +%Y-%m-%d)"
+export TARGET_BRANCH="nixpkgs-upgrade-$(date +%Y-%m-%d)"
 
 echo '{}' > morph/grid/local/public-keys/users.nix
 # nix-build -A morph -o result-before