diff --git a/pkgs/development/python-modules/chex/default.nix b/pkgs/development/python-modules/chex/default.nix
index 588ca836ad8f1..b93d3baddcc4a 100644
--- a/pkgs/development/python-modules/chex/default.nix
+++ b/pkgs/development/python-modules/chex/default.nix
@@ -1,5 +1,6 @@
 { absl-py
 , buildPythonPackage
+, cloudpickle
 , dm-tree
 , fetchFromGitHub
 , jax
@@ -24,6 +25,7 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [
     absl-py
+    cloudpickle
     dm-tree
     jax
     numpy