diff --git a/artiq/firmware/cargosha256.nix b/artiq/firmware/cargosha256.nix
new file mode 100644
index 000000000..c356e4291
--- /dev/null
+++ b/artiq/firmware/cargosha256.nix
@@ -0,0 +1 @@
+"1xzjn9i4rkd9124v2gbdplsgsvp1hlx7czdgc58n316vsnrkbr86"