diff --git a/pkgs/development/python-modules/gymnasium/default.nix b/pkgs/development/python-modules/gymnasium/default.nix
index d9088c43d27c..f81312e97e58 100644
--- a/pkgs/development/python-modules/gymnasium/default.nix
+++ b/pkgs/development/python-modules/gymnasium/default.nix
@@ -15,6 +15,10 @@
   pythonOlder,
   importlib-metadata,
 
+  # optional-dependencies
+  # atari
+  ale-py,
+
   # tests
   array-api-compat,
   dill,
@@ -54,6 +58,12 @@ buildPythonPackage rec {
     typing-extensions
   ] ++ lib.optionals (pythonOlder "3.10") [ importlib-metadata ];
 
+  optional-dependencies = {
+    atari = [
+      ale-py
+    ];
+  };
+
   pythonImportsCheck = [ "gymnasium" ];
 
   nativeCheckInputs = [