diff --git a/lib/default.nix b/lib/default.nix
index 574713e48..94a81439e 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -52,6 +52,7 @@ let
       type = typeOf x;
       reject = throw "cannot convert ${type}";
     in {
+      int = toJSON x; # close enough
       list = "{ ${concatStringsSep ", " (map toC x)} }";
       null = "NULL";
       set = if isDerivation x then toJSON x else reject;