diff --git a/os/rebuild.sh b/os/rebuild.sh
index 2c69f36..7fa3243 100644
--- a/os/rebuild.sh
+++ b/os/rebuild.sh
@@ -21,7 +21,7 @@ rm -rf "$tmpdir"
 nvd diff /nix/var/nix/profiles/system "$toplevel"
 
 # Figure out specialisation
-specialisationArgs=""
+specialisationArgs=()
 currentSystem="$(readlink /run/current-system)"
 while read -r specialisation
 do