diff --git a/artiq-fast/artiq-board.nix b/artiq-fast/artiq-board.nix
index d9eb4a4..3599bf1 100644
--- a/artiq-fast/artiq-board.nix
+++ b/artiq-fast/artiq-board.nix
@@ -94,7 +94,7 @@ pkgs.python3Packages.toPythonModule (pkgs.stdenv.mkDerivation rec {
         artiqpkgs.binutils-or1k
         artiqpkgs.llvm-or1k
       ]);
-  buildInputs = [ (pkgs.python3.withPackages(ps: with ps; [ jinja2 numpy artiqpkgs.migen artiqpkgs.microscope artiqpkgs.misoc artiqpkgs.jesd204b artiqpkgs.artiq ])) ];
+  buildInputs = [ (pkgs.python3.withPackages(ps: with ps; [ artiqpkgs.migen artiqpkgs.microscope artiqpkgs.misoc artiqpkgs.jesd204b artiqpkgs.artiq ] ++ (pkgs.lib.optional artiq7 jsonschema))) ];
   buildPhase = if artiq7
     then
       ''