diff --git a/terranix/lib/build_nixng_system.nix b/terranix/lib/build_nixng_system.nix
index e2acd62..27b3d2d 100644
--- a/terranix/lib/build_nixng_system.nix
+++ b/terranix/lib/build_nixng_system.nix
@@ -45,8 +45,9 @@ in {
 
           cd $FLAKE_ROOT
           nix build "${flakePath}"
+          mkdir -p /tmp/terranix
           ${concatMapStringsSep "\n" (host: ''
-              flock /tmp/terranix/${host} -x nix copy "$_system_path" --to ssh-ng://${host} -s --no-check-sigs
+              flock -x /tmp/terranix/${host} nix copy "$_system_path" --to ssh-ng://${host} -s --no-check-sigs
             '')
             hosts}