diff --git a/flake.nix b/flake.nix
index 9fc6703..30c20db 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,6 +43,7 @@
         nativeBuildInputs = with pkgs; [
           curl
           jq
+          minisign
           python3Full
         ];
       };
diff --git a/update b/update
index 57e0d64..2bf9db5 100755
--- a/update
+++ b/update
@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#! nix-shell -p curl jq python3Full -i sh
+#! nix-shell -p curl jq minisign python3Full -i sh
 set -e
 
 # Build our new sources.json