diff --git a/nixos/modules/services/development/jupyter/default.nix b/nixos/modules/services/development/jupyter/default.nix
index 9b0178d3ea68..c3ef040ebe65 100644
--- a/nixos/modules/services/development/jupyter/default.nix
+++ b/nixos/modules/services/development/jupyter/default.nix
@@ -119,7 +119,7 @@ in {
 
     kernels = mkOption {
       type = types.nullOr (types.attrsOf(types.submodule (import ./kernel-options.nix {
-        inherit lib;
+        inherit lib pkgs;
       })));
 
       default = null;
diff --git a/nixos/modules/services/development/jupyter/kernel-options.nix b/nixos/modules/services/development/jupyter/kernel-options.nix
index 3c91d531b0ef..6e406152de47 100644
--- a/nixos/modules/services/development/jupyter/kernel-options.nix
+++ b/nixos/modules/services/development/jupyter/kernel-options.nix
@@ -1,9 +1,11 @@
 # Options that can be used for creating a jupyter kernel.
-{ lib }:
+{ lib, pkgs }:
 
 with lib;
 
 {
+  freeformType = (pkgs.formats.json { }).type;
+
   options = {
 
     displayName = mkOption {
diff --git a/nixos/modules/services/development/jupyterhub/default.nix b/nixos/modules/services/development/jupyterhub/default.nix
index c0c0734cac09..cebc35a50476 100644
--- a/nixos/modules/services/development/jupyterhub/default.nix
+++ b/nixos/modules/services/development/jupyterhub/default.nix
@@ -119,7 +119,7 @@ in {
 
     kernels = mkOption {
       type = types.nullOr (types.attrsOf(types.submodule (import ../jupyter/kernel-options.nix {
-        inherit lib;
+        inherit lib pkgs;
       })));
 
       default = null;